21913570 has 32 divisors (see below), whose sum is σ = 45255168. Its totient is φ = 7483968.

The previous prime is 21913543. The next prime is 21913571. The reversal of 21913570 is 7531912.

It is not an unprimeable number, because it can be changed into a prime (21913571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25264 + ... + 26116.

It is an arithmetic number, because the mean of its divisors is an integer number (1414224).

Almost surely, 2^21913570 is an apocalyptic number.

21913570 is an abundant number, since it is smaller than the sum of its proper divisors (23341598).

21913570 is a wasteful number, since it uses less digits than its factorization.

21913570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 21913570 is about 4681.1932239548. The cubic root of 21913570 is about 279.8365117028.

The spelling of 21913570 in words is "twenty-one million, nine hundred thirteen thousand, five hundred seventy".