21563992131 has 12 divisors (see below), whose sum is σ = 31603427016. Its totient is φ = 13069085920.

The previous prime is 21563992123. The next prime is 21563992139. The reversal of 21563992131 is 13129936512.

It is an interprime number because it is at equal distance from previous prime (21563992123) and next prime (21563992139).

It is not a de Polignac number, because 21563992131 - 2³ = 21563992123 is a prime.

It is a super-2 number, since 2×21563992131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21563992139) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29702106 + ... + 29702831.

It is an arithmetic number, because the mean of its divisors is an integer number (2633618918).

Almost surely, 2^21563992131 is an apocalyptic number.

21563992131 is a deficient number, since it is larger than the sum of its proper divisors (10039434885).

21563992131 is a wasteful number, since it uses less digits than its factorization.

21563992131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59404962 (or 59404951 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The spelling of 21563992131 in words is "twenty-one billion, five hundred sixty-three million, nine hundred ninety-two thousand, one hundred thirty-one".