21057572 has 12 divisors (see below), whose sum is σ = 37475760. Its totient is φ = 10350216.

The previous prime is 21057563. The next prime is 21057599. The reversal of 21057572 is 27575012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44378 + ... + 44849.

It is an arithmetic number, because the mean of its divisors is an integer number (3122980).

Almost surely, 2^21057572 is an apocalyptic number.

It is an amenable number.

21057572 is a deficient number, since it is larger than the sum of its proper divisors (16418188).

21057572 is a wasteful number, since it uses less digits than its factorization.

21057572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89290 (or 89288 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 21057572 is about 4588.8530157328. The cubic root of 21057572 is about 276.1443094663.

The spelling of 21057572 in words is "twenty-one million, fifty-seven thousand, five hundred seventy-two".