Natural number
40,000 (forty thousand) is the natural number that comes after 39,999 and before 40,001. It is the square of 200.
Selected numbers in the range 40001–49999
40001 to 40999
41000 to 41999
42000 to 42999
43000 to 43999
- 43261 = Markov number[10]
- 43380 = number of nets of a dodecahedron
- 43390 = number of primes
.[11]
- 43560 = pentagonal pyramidal number
- 43691 = Wagstaff prime[12]
- 43777 = smallest member of a prime sextuplet
44000 to 44999
- 44044 = palindrome of 79 after 6 iterations of the "reverse and add" iterative process[13]
- 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[14]
- 44721 = smallest positive integer such that the expression 1/n − 1/n + 2 ≤ 10−9
- 44944 = palindromic square
45000 to 45999
46000 to 46999
47000 to 47999
48000 to 48999
- 48734 = number of 22-bead necklaces (turning over is allowed) where complements are equivalent[20]
49000 to 49999
- 49151 = Woodall number[21]
- 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[22]
Primes
There are 930 prime numbers between 40000 and 50000.