21920570 has 16 divisors (see below), whose sum is σ = 45093888. Its totient is φ = 7515600.

The previous prime is 21920551. The next prime is 21920573. The reversal of 21920570 is 7502912.

It is a super-2 number, since 2×21920570² = 961022778249800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21920573) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156506 + ... + 156645.

It is an arithmetic number, because the mean of its divisors is an integer number (2818368).

Almost surely, 2^21920570 is an apocalyptic number.

21920570 is an abundant number, since it is smaller than the sum of its proper divisors (23173318).

21920570 is a wasteful number, since it uses less digits than its factorization.

21920570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313165.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 21920570 is about 4681.9408368752. The cubic root of 21920570 is about 279.8663052210.

The spelling of 21920570 in words is "twenty-one million, nine hundred twenty thousand, five hundred seventy".