21875210 has 64 divisors (see below), whose sum is σ = 47139840. Its totient is φ = 7153920.

The previous prime is 21875207. The next prime is 21875233. The reversal of 21875210 is 1257812.

It is a self number, because there is not a number n which added to its sum of digits gives 21875210.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 200636 + ... + 200744.

It is an arithmetic number, because the mean of its divisors is an integer number (736560).

Almost surely, 2^21875210 is an apocalyptic number.

21875210 is an abundant number, since it is smaller than the sum of its proper divisors (25264630).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21875210 is a wasteful number, since it uses less digits than its factorization.

21875210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 21875210 is about 4677.0941833579. The cubic root of 21875210 is about 279.6731304686.

The spelling of 21875210 in words is "twenty-one million, eight hundred seventy-five thousand, two hundred ten".