21056124 has 24 divisors (see below), whose sum is σ = 50330448. Its totient is φ = 6847360.

The previous prime is 21056089. The next prime is 21056129. The reversal of 21056124 is 42165012.

It is a self number, because there is not a number n which added to its sum of digits gives 21056124.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20907 + ... + 21890.

It is an arithmetic number, because the mean of its divisors is an integer number (2097102).

Almost surely, 2^21056124 is an apocalyptic number.

It is an amenable number.

21056124 is an abundant number, since it is smaller than the sum of its proper divisors (29274324).

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

21056124 is a wasteful number, since it uses less digits than its factorization.

21056124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42845 (or 42843 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21056124 is about 4588.6952393900. The cubic root of 21056124 is about 276.1379797380.

The spelling of 21056124 in words is "twenty-one million, fifty-six thousand, one hundred twenty-four".