21316732605 has 128 divisors (see below), whose sum is σ = 47162880000. Its totient is φ = 8913348864.

The previous prime is 21316732589. The next prime is 21316732609. The reversal of 21316732605 is 50623761312.

21316732605 is a `hidden beast` number, since 2 + 1 + 3 + 16 + 7 + 32 + 605 = 666.

It is not a de Polignac number, because 21316732605 - 2⁴ = 21316732589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21316732605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316732609) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 500226 + ... + 541164.

It is an arithmetic number, because the mean of its divisors is an integer number (368460000).

Almost surely, 2^21316732605 is an apocalyptic number.

It is an amenable number.

21316732605 is an abundant number, since it is smaller than the sum of its proper divisors (25846147395).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21316732605 is a wasteful number, since it uses less digits than its factorization.

21316732605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41008 (or 41002 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The spelling of 21316732605 in words is "twenty-one billion, three hundred sixteen million, seven hundred thirty-two thousand, six hundred five".