21602765813631 has 16 divisors (see below), whose sum is σ = 28820465817600. Its totient is φ = 14393456539488.

The previous prime is 21602765813597. The next prime is 21602765813647. The reversal of 21602765813631 is 13631856720612.

It is a de Polignac number, because none of the positive numbers 2^k-21602765813631 is a prime.

It is a super-2 number, since 2×21602765813631² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21602765814631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51959805 + ... + 52373913.

It is an arithmetic number, because the mean of its divisors is an integer number (1801279113600).

Almost surely, 2^{21602765813631} is an apocalyptic number.

21602765813631 is a deficient number, since it is larger than the sum of its proper divisors (7217700003969).

21602765813631 is a wasteful number, since it uses less digits than its factorization.

21602765813631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424198.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 21602765813631 in words is "twenty-one trillion, six hundred two billion, seven hundred sixty-five million, eight hundred thirteen thousand, six hundred thirty-one".