21055056 has 40 divisors (see below), whose sum is σ = 59338464. Its totient is φ = 6380160.

The previous prime is 21055043. The next prime is 21055063. The reversal of 21055056 is 65055012.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 19411 + ... + 20466.

Almost surely, 2^21055056 is an apocalyptic number.

It is an amenable number.

21055056 is an abundant number, since it is smaller than the sum of its proper divisors (38283408).

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

21055056 is a wasteful number, since it uses less digits than its factorization.

21055056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39899 (or 39893 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 21055056 is about 4588.5788649646. The cubic root of 21055056 is about 276.1333109403.

It can be divided in two parts, 2 and 1055056, that multiplied together give a palindrome (2110112).

The spelling of 21055056 in words is "twenty-one million, fifty-five thousand, fifty-six".