21072396 has 24 divisors (see below), whose sum is σ = 49263424. Its totient is φ = 7010640.

The previous prime is 21072379. The next prime is 21072407. The reversal of 21072396 is 69327012.

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, 6351 + ... + 9081.

Almost surely, 2^21072396 is an apocalyptic number.

It is an amenable number.

21072396 is an abundant number, since it is smaller than the sum of its proper divisors (28191028).

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

21072396 is a wasteful number, since it uses less digits than its factorization.

21072396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3381 (or 3379 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21072396 is about 4590.4679500025. The cubic root of 21072396 is about 276.2090938113.

The spelling of 21072396 in words is "twenty-one million, seventy-two thousand, three hundred ninety-six".