21255877904 has 20 divisors (see below), whose sum is σ = 43350804240. Its totient is φ = 10068573600.

The previous prime is 21255877901. The next prime is 21255877939. The reversal of 21255877904 is 40977855212.

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21255877901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34960022 + ... + 34960629.

It is an arithmetic number, because the mean of its divisors is an integer number (2167540212).

Almost surely, 2^21255877904 is an apocalyptic number.

It is an amenable number.

21255877904 is an abundant number, since it is smaller than the sum of its proper divisors (22094926336).

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

21255877904 is a wasteful number, since it uses less digits than its factorization.

21255877904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69920678 (or 69920672 counting only the distinct ones).

The product of its (nonzero) digits is 1411200, while the sum is 50.

The spelling of 21255877904 in words is "twenty-one billion, two hundred fifty-five million, eight hundred seventy-seven thousand, nine hundred four".