40,000

Short description: Natural number

← 39999 40000 40001 →
List of numbers — Integers ← 0 10k 20k 30k 40k 50k 60k 70k 80k 90k →
Cardinal	forty thousand
Ordinal	40000th (forty thousandth)
Factorization	26 × 54
Divisors	35 total
Greek numeral	[math]\displaystyle{ \stackrel{\delta}{\Mu} }[/math]
Roman numeral	XL
Binary	10011100010000002
Ternary	20002121113
Quaternary	213010004
Quinary	22400005
Senary	5051046
Octal	1161008
Duodecimal	1B19412
Hexadecimal	9C4016
Vigesimal	500020
Base 36	UV436

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

• 40320 = smallest factorial (8!) that is not a highly composite number
• 40425 = square pyramidal number
• 40585 = largest factorion
• 40678 = pentagonal pyramidal number
• 40804 = palindromic square

41000 to 41999

• 41041 = Carmichael number
• 41472 = 3-smooth number
• 41586 = Large Schröder number
• 41616 = triangular square number
• 41835 = Motzkin number
• 41841 = 1/41841 = 0.0000239 is a repeating decimal with period 7.

42000 to 42999

• 42680 = octahedral number
• 42875 = 35³
• 42925 = square pyramidal number

43000 to 43999

• 43261 = Markov number
• 43390 = number of primes [math]\displaystyle{ \leq 2^{19} }[/math].
• 43560 = pentagonal pyramidal number
• 43691 = Wagstaff prime

44000 to 44999

• 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
• 44721 = smallest positive integer such that the expression 1/n − 1/n + 2 ≤ 10⁻⁹
• 44944 = palindromic square

45000 to 45999

• 45360 = highly composite number; first number to have 100 factors (including one and itself)

46000 to 46999

• 46233 = sum of the first eight factorials
• 46368 = Fibonacci number
• 46656 = 36³, 6⁶, 3-smooth number
• 46657 = Carmichael number
• 46664 = Nelson Mandela's prisoner number

47000 to 47999

• 47058 = primary pseudoperfect number
• 47160 = 10-th derivative of x^x at x=1
• 47321/33461 ≈ √2

49000 to 49999

• 49151 = Woodall number
• 49152 = 3-smooth number
• 49726 = pentagonal pyramidal number