21255456120 has 32 divisors (see below), whose sum is σ = 63766368720. Its totient is φ = 5668121600.

The previous prime is 21255456113. The next prime is 21255456151. The reversal of 21255456120 is 2165455212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88564281 + ... + 88564520.

Almost surely, 2^21255456120 is an apocalyptic number.

21255456120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21255456120 is an abundant number, since it is smaller than the sum of its proper divisors (42510912600).

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

21255456120 is a wasteful number, since it uses less digits than its factorization.

21255456120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177128815 (or 177128811 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 33.

The spelling of 21255456120 in words is "twenty-one billion, two hundred fifty-five million, four hundred fifty-six thousand, one hundred twenty".