21700570 has 16 divisors (see below), whose sum is σ = 39115080. Its totient is φ = 8668224.

The previous prime is 21700561. The next prime is 21700573. The reversal of 21700570 is 7500712.

It can be written as a sum of positive squares in 4 ways, for example, as 17065161 + 4635409 = 4131^2 + 2153^2 .

It is not an unprimeable number, because it can be changed into a prime (21700573) 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, 11236 + ... + 13024.

Almost surely, 2^21700570 is an apocalyptic number.

21700570 is a deficient number, since it is larger than the sum of its proper divisors (17414510).

21700570 is a wasteful number, since it uses less digits than its factorization.

21700570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3009.

The product of its (nonzero) digits is 490, while the sum is 22.

The square root of 21700570 is about 4658.3870599168. The cubic root of 21700570 is about 278.9268873997.

The spelling of 21700570 in words is "twenty-one million, seven hundred thousand, five hundred seventy".