21631413663 has 8 divisors (see below), whose sum is σ = 32046538800. Its totient is φ = 14420942424.

The previous prime is 21631413653. The next prime is 21631413691. The reversal of 21631413663 is 36631413612.

21631413663 is a `hidden beast` number, since 2 + 1 + 631 + 4 + 13 + 6 + 6 + 3 = 666.

It is not a de Polignac number, because 21631413663 - 2⁵ = 21631413631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21631413653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 400581708 + ... + 400581761.

It is an arithmetic number, because the mean of its divisors is an integer number (4005817350).

Almost surely, 2^21631413663 is an apocalyptic number.

21631413663 is a deficient number, since it is larger than the sum of its proper divisors (10415125137).

21631413663 is an equidigital number, since it uses as much as digits as its factorization.

21631413663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801163478 (or 801163472 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

The spelling of 21631413663 in words is "twenty-one billion, six hundred thirty-one million, four hundred thirteen thousand, six hundred sixty-three".