21228076 has 12 divisors (see below), whose sum is σ = 37183720. Its totient is φ = 10604160.

The previous prime is 21228059. The next prime is 21228089. The reversal of 21228076 is 67082212.

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, 4636 + ... + 7996.

Almost surely, 2^21228076 is an apocalyptic number.

It is an amenable number.

21228076 is a deficient number, since it is larger than the sum of its proper divisors (15955644).

21228076 is a wasteful number, since it uses less digits than its factorization.

21228076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4944 (or 4942 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21228076 is about 4607.3936232972. The cubic root of 21228076 is about 276.8876240068.

The spelling of 21228076 in words is "twenty-one million, two hundred twenty-eight thousand, seventy-six".