21917130 has 16 divisors (see below), whose sum is σ = 52601184. Its totient is φ = 5844560.

The previous prime is 21917113. The next prime is 21917149. The reversal of 21917130 is 3171912.

It is a self number, because there is not a number n which added to its sum of digits gives 21917130.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365256 + ... + 365315.

It is an arithmetic number, because the mean of its divisors is an integer number (3287574).

Almost surely, 2^21917130 is an apocalyptic number.

21917130 is an abundant number, since it is smaller than the sum of its proper divisors (30684054).

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

21917130 is a wasteful number, since it uses less digits than its factorization.

21917130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730581.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 21917130 is about 4681.5734534449. The cubic root of 21917130 is about 279.8516646276.

The spelling of 21917130 in words is "twenty-one million, nine hundred seventeen thousand, one hundred thirty".