21056520501 has 48 divisors (see below), whose sum is σ = 32760262080. Its totient is φ = 12985689600.

The previous prime is 21056520469. The next prime is 21056520509. The reversal of 21056520501 is 10502565012.

21056520501 is a `hidden beast` number, since 2 + 1 + 0 + 5 + 652 + 0 + 5 + 0 + 1 = 666.

It is not a de Polignac number, because 21056520501 - 2⁵ = 21056520469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056520509) 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, 2143066 + ... + 2152868.

It is an arithmetic number, because the mean of its divisors is an integer number (682505460).

Almost surely, 2^21056520501 is an apocalyptic number.

It is an amenable number.

21056520501 is a deficient number, since it is larger than the sum of its proper divisors (11703741579).

21056520501 is a wasteful number, since it uses less digits than its factorization.

21056520501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10066 (or 10063 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The spelling of 21056520501 in words is "twenty-one billion, fifty-six million, five hundred twenty thousand, five hundred one".