21255530224 has 20 divisors (see below), whose sum is σ = 42973137936. Its totient is φ = 10165688192.

The previous prime is 21255530221. The next prime is 21255530237. The reversal of 21255530224 is 42203555212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255530221) 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, 28879429 + ... + 28880164.

Almost surely, 2^21255530224 is an apocalyptic number.

It is an amenable number.

21255530224 is an abundant number, since it is smaller than the sum of its proper divisors (21717607712).

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

21255530224 is a wasteful number, since it uses less digits than its factorization.

21255530224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57759624 (or 57759618 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 31.

The spelling of 21255530224 in words is "twenty-one billion, two hundred fifty-five million, five hundred thirty thousand, two hundred twenty-four".