21526625221 has 16 divisors (see below), whose sum is σ = 22799790720. Its totient is φ = 20282296320.

The previous prime is 21526625189. The next prime is 21526625227. The reversal of 21526625221 is 12252662512.

It is a cyclic number.

It is not a de Polignac number, because 21526625221 - 2⁵ = 21526625189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21526625227) 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, 1353765 + ... + 1369573.

It is an arithmetic number, because the mean of its divisors is an integer number (1424986920).

Almost surely, 2^21526625221 is an apocalyptic number.

It is an amenable number.

21526625221 is a deficient number, since it is larger than the sum of its proper divisors (1273165499).

21526625221 is a wasteful number, since it uses less digits than its factorization.

21526625221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16716.

The product of its digits is 28800, while the sum is 34.

The spelling of 21526625221 in words is "twenty-one billion, five hundred twenty-six million, six hundred twenty-five thousand, two hundred twenty-one".