21056524 has 12 divisors (see below), whose sum is σ = 36994104. Its totient is φ = 10486784.

The previous prime is 21056507. The next prime is 21056527. The reversal of 21056524 is 42565012.

It is not an unprimeable number, because it can be changed into a prime (21056527) 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, 9214 + ... + 11269.

It is an arithmetic number, because the mean of its divisors is an integer number (3082842).

Almost surely, 2^21056524 is an apocalyptic number.

It is an amenable number.

21056524 is a deficient number, since it is larger than the sum of its proper divisors (15937580).

21056524 is a wasteful number, since it uses less digits than its factorization.

21056524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20744 (or 20742 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 21056524 is about 4588.7388245574. The cubic root of 21056524 is about 276.1397283108.

The spelling of 21056524 in words is "twenty-one million, fifty-six thousand, five hundred twenty-four".