21379506 has 32 divisors (see below), whose sum is σ = 45515520. Its totient is φ = 6671616.

The previous prime is 21379493. The next prime is 21379517. The reversal of 21379506 is 60597312.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23940 + ... + 24816.

It is an arithmetic number, because the mean of its divisors is an integer number (1422360).

Almost surely, 2^21379506 is an apocalyptic number.

21379506 is an abundant number, since it is smaller than the sum of its proper divisors (24136014).

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

21379506 is a wasteful number, since it uses less digits than its factorization.

21379506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1138.

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 21379506 is about 4623.7977896963. The cubic root of 21379506 is about 277.5444551781.

The spelling of 21379506 in words is "twenty-one million, three hundred seventy-nine thousand, five hundred six".