40,000#40001 to 40999

• 40320 = smallest factorial (8!) that is not a highly composite number
• 40425 = square pyramidal number
• 40585 = largest factorion{{Cite web|url=https://oeis.org/A014080|title=Sloane's A014080 : Factorions|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 40678 = pentagonal pyramidal number
• 40755 = the smallest number >1 to be a Triangular number, Pentagonal number, and a Hexagonal number.{{Cite web |title=A046180 - OEIS |url=https://oeis.org/A046180 |access-date=2024-12-18 |website=oeis.org}} Additionally, it's a 390-gonal, 4077-gonal, and 13586-gonal number.{{cite OEIS|A000217|Triangular numbers}}{{cite OEIS|A000326|Pentagonal numbers}}{{cite OEIS|A000384|Hexagonal numbers}}
• 40804 = palindromic square

• 41041 = Carmichael number{{Cite web|url=https://oeis.org/A002997|title=Sloane's A002997 : Carmichael numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 41472 = 3-smooth number, number of reduced trees with 24 nodes{{cite OEIS|A000014|Number of series-reduced trees with n nodes}}
• 41586 = Large Schröder number
• 41616 = triangular square number{{Cite web|url=https://oeis.org/A001110|title=Sloane's A001110 : Square triangular numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 41835 = Motzkin number{{Cite web|url=https://oeis.org/A001006|title=Sloane's A001006 : Motzkin numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 41841 = 1/41841 = 0.0000239 is a repeating decimal with period 7

• 42680 = octahedral number{{Cite web|url=https://oeis.org/A005900|title=Sloane's A005900 : Octahedral numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 42875 = 35³
• 42925 = square pyramidal number

• 43261 = Markov number{{Cite web|url=https://oeis.org/A002559|title=Sloane's A002559 : Markoff (or Markov) numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-06-15}}
• 43380 = number of nets of a dodecahedron
• 43390 = number of primes $\backslash leq\; 2^\{19\}$.{{cite OEIS|A007053|2=Number of primes <= 2^n}}
• 43560 = pentagonal pyramidal number
• 43691 = Wagstaff prime{{Cite OEIS|A000979|Wagstaff primes}}
• 43777 = smallest member of a prime sextuplet

• 44044 = palindrome of 79 after 6 iterations of the "reverse and add" iterative process{{cite web|url=http://jasondoucette.com/pal/79|title=Reversal-Addition Palindrome Test on 79}}
• 44100 = sum of the cubes of the first 20 positive integers 44,100 Hz is a common sampling frequency in digital audio (and is the standard for compact discs).
• 44444 = repdigit
• 44583 = number of partitions of 41{{cite OEIS|A000041|a(n) is the number of partitions of n (the partition numbers)}}
• 44721 = smallest positive integer such that the expression {{sfrac|1|n}} − {{sfrac|1|n + 2}} ≤ 10⁻⁹
• 44724 = maximum number of days in which a human being has been verified to live (Jeanne Calment).{{cite book |last1=Amzallag |first1=William |title=The Promise of Immortality |url=https://books.google.com/books?id=AQI0DQAAQBAJ&dq=44724+days+old&pg=PA12|page=12 |date=22 September 2016 |publisher=Varegus Publishing |isbn=978-2-9558558-1-2 |access-date=September 22, 2016}}
• 44944 = palindromic square

• 45360 = 26th highly composite number;{{Cite OEIS|A002182|Highly composite numbers}} smallest number with exactly 100 factors (including one and itself)

• 46080 = double factorial of 12
• 46233 = sum of the first eight factorials
• 46249 = 2nd number that can be written as $a^2+b!$ in 3 ways{{cite OEIS|A359013|Numbers k that can be written as the sum of a perfect square and a factorial in exactly 3 distinct ways}}
• 46368 = Fibonacci number{{Cite OEIS|A000045|Fibonacci numbers}}
• 46656 = 216{{sup|2}} = 36{{sup|3}} = 6⁶, 3-smooth number
• 46657 = Carmichael number
• 46972 = number of prime knots with 14 crossings

• 47058 = primary pseudoperfect number{{Cite OEIS|A054377|Primary pseudoperfect numbers}}
• 47160 = 10-th derivative of x^x at x=1{{cite OEIS|A005727|2=n-th derivative of x^x at x=1. Also called Lehmer-Comtet numbers}}
• 47321/33461 ≈ √2

• 48629 = number of trees with 17 unlabeled nodes{{cite OEIS|A000055|Number of trees with n unlabeled nodes}}
• 48734 = number of 22-bead necklaces (turning over is allowed) where complements are equivalent{{cite OEIS|A000011|Number of n-bead necklaces (turning over is allowed) where complements are equivalent}}

• 49151 = Woodall number{{Cite OEIS|A003261|Woodall numbers}}
• 49152 = 3-smooth number
• 49726 = pentagonal pyramidal number
• 49940 = number of 21-bead binary necklaces with beads of 2 colors where the colors may be swapped but turning over is not allowed{{cite OEIS|A000013|Definition (1): Number of n-bead binary necklaces with beads of 2 colors where the colors may be swapped but turning over is not allowed}}

There are 930 prime numbers between 40000 and 50000.

{{Reflist}}

{{Integers|10}}

40000