40000 (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 40000–49999

• 40000 – round number, 200²
• 40320 – smallest factorial that is not a highly composite number
• 40425 – square pyramidal number
• 40585 – largest factorion^[1]
• 40678 – pentagonal pyramidal number
• 40804 – palindromic square
• 41041 – Carmichael number^[2]
• 41616 – triangular square number^[3]
• 41835 – Motzkin number^[4]
• 42680 – octahedral number^[5]
• 42875 – 35³
• 42925 – square pyramidal number
• 43261 – Markov number^[6]
• 43560 – pentagonal pyramidal number
• 43691 – Wagstaff prime^[7]
• 44100 – sum of the cubes of the first 20 positive integers, sampling rate of Red Book-compliant audio compact disks
• 44721 – When n > 44721, the expression 1/n − 1/n + 2 drops down to fractions of a billionth. The corresponding sum in the Leibniz formula for pi is 0.785386986.
• 44944 – palindromic square
• 45360 – highly composite number;^[8] first number to have 100 factors (including one and itself)
• 46233 – sum of the first eight factorials
• 46368 – Fibonacci number^[9]
• 46656 – 6⁶
• 46657 – Carmichael number^[2]
• 46664 – Nelson Mandela's prisoner number
• 47058 – primary pseudoperfect number^[10]
• 47806 – in hexadecimal it is written as "BABE"
• 49151 – Woodall number^[11]
• 49726 – pentagonal pyramidal number

References