21402392 has 16 divisors (see below), whose sum is σ = 43777800. Its totient is φ = 9728320.

The previous prime is 21402383. The next prime is 21402401. The reversal of 21402392 is 29320412.

It is an interprime number because it is at equal distance from previous prime (21402383) and next prime (21402401).

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, 121517 + ... + 121692.

Almost surely, 2^21402392 is an apocalyptic number.

21402392 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21402392 is an abundant number, since it is smaller than the sum of its proper divisors (22375408).

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

21402392 is a wasteful number, since it uses less digits than its factorization.

21402392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243226 (or 243222 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21402392 is about 4626.2719332093. The cubic root of 21402392 is about 277.6434536810.

The spelling of 21402392 in words is "twenty-one million, four hundred two thousand, three hundred ninety-two".