21264104565 has 96 divisors (see below), whose sum is σ = 42217718400. Its totient is φ = 9805340160.

The previous prime is 21264104531. The next prime is 21264104569. The reversal of 21264104565 is 56540146212.

21264104565 is a `hidden beast` number, since 2 + 1 + 2 + 641 + 0 + 4 + 5 + 6 + 5 = 666.

It is not a de Polignac number, because 21264104565 - 2⁷ = 21264104437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264104569) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 950731 + ... + 972839.

It is an arithmetic number, because the mean of its divisors is an integer number (439767900).

Almost surely, 2^21264104565 is an apocalyptic number.

It is an amenable number.

21264104565 is a deficient number, since it is larger than the sum of its proper divisors (20953613835).

21264104565 is a wasteful number, since it uses less digits than its factorization.

21264104565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22227 (or 22224 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 21264104565 in words is "twenty-one billion, two hundred sixty-four million, one hundred four thousand, five hundred sixty-five".