21731139575 has 6 divisors (see below), whose sum is σ = 26946613104. Its totient is φ = 17384911640.

The previous prime is 21731139571. The next prime is 21731139581. The reversal of 21731139575 is 57593113712.

It is not a de Polignac number, because 21731139575 - 2² = 21731139571 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21731139571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 434622767 + ... + 434622816.

It is an arithmetic number, because the mean of its divisors is an integer number (4491102184).

Almost surely, 2^21731139575 is an apocalyptic number.

21731139575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21731139575 is a deficient number, since it is larger than the sum of its proper divisors (5215473529).

21731139575 is an equidigital number, since it uses as much as digits as its factorization.

21731139575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869245593 (or 869245588 counting only the distinct ones).

The product of its digits is 198450, while the sum is 44.

The spelling of 21731139575 in words is "twenty-one billion, seven hundred thirty-one million, one hundred thirty-nine thousand, five hundred seventy-five".