21393308 has 12 divisors (see below), whose sum is σ = 38351712. Its totient is φ = 10435680.

The previous prime is 21393299. The next prime is 21393313. The reversal of 21393308 is 80339312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65060 + ... + 65387.

It is an arithmetic number, because the mean of its divisors is an integer number (3195976).

Almost surely, 2^21393308 is an apocalyptic number.

It is an amenable number.

21393308 is a deficient number, since it is larger than the sum of its proper divisors (16958404).

21393308 is a wasteful number, since it uses less digits than its factorization.

21393308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130492 (or 130490 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 21393308 is about 4625.2900449593. The cubic root of 21393308 is about 277.6041672616.

The spelling of 21393308 in words is "twenty-one million, three hundred ninety-three thousand, three hundred eight".