21631005525 has 48 divisors (see below), whose sum is σ = 37690365440. Its totient is φ = 10916337600.

The previous prime is 21631005521. The next prime is 21631005559. The reversal of 21631005525 is 52550013612.

It is a happy number.

It is not a de Polignac number, because 21631005525 - 2² = 21631005521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21631005492 and 21631005501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631005521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1249680 + ... + 1266870.

Almost surely, 2^21631005525 is an apocalyptic number.

21631005525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21631005525 is a deficient number, since it is larger than the sum of its proper divisors (16059359915).

21631005525 is a wasteful number, since it uses less digits than its factorization.

21631005525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18106 (or 18101 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21631005525 in words is "twenty-one billion, six hundred thirty-one million, five thousand, five hundred twenty-five".