21357012 has 24 divisors (see below), whose sum is σ = 49969696. Its totient is φ = 7099488.

The previous prime is 21356989. The next prime is 21357031. The reversal of 21357012 is 21075312.

It is a super-2 number, since 2×21357012² = 912243923136288, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21357012.

It is a congruent number.

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, 2523 + ... + 7005.

Almost surely, 2^21357012 is an apocalyptic number.

It is an amenable number.

21357012 is an abundant number, since it is smaller than the sum of its proper divisors (28612684).

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

21357012 is a wasteful number, since it uses less digits than its factorization.

21357012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4887 (or 4885 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21357012 is about 4621.3647334959. The cubic root of 21357012 is about 277.4470834901.

The spelling of 21357012 in words is "twenty-one million, three hundred fifty-seven thousand, twelve".