21363390 has 48 divisors (see below), whose sum is σ = 58816368. Its totient is φ = 5361408.

The previous prime is 21363383. The next prime is 21363409. The reversal of 21363390 is 9336312.

21363390 is a `hidden beast` number, since 21 + 3 + 633 + 9 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5452 + ... + 8511.

It is an arithmetic number, because the mean of its divisors is an integer number (1225341).

Almost surely, 2^21363390 is an apocalyptic number.

21363390 is an abundant number, since it is smaller than the sum of its proper divisors (37452978).

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

21363390 is a wasteful number, since it uses less digits than its factorization.

21363390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13993 (or 13990 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 27.

The square root of 21363390 is about 4622.0547378844. The cubic root of 21363390 is about 277.4746994221.

The spelling of 21363390 in words is "twenty-one million, three hundred sixty-three thousand, three hundred ninety".