21268816 has 20 divisors (see below), whose sum is σ = 42086592. Its totient is φ = 10407776.

The previous prime is 21268801. The next prime is 21268823. The reversal of 21268816 is 61886212.

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, 13390 + ... + 14893.

Almost surely, 2^21268816 is an apocalyptic number.

It is an amenable number.

21268816 is a deficient number, since it is larger than the sum of its proper divisors (20817776).

21268816 is a wasteful number, since it uses less digits than its factorization.

21268816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28338 (or 28332 counting only the distinct ones).

The product of its digits is 9216, while the sum is 34.

The square root of 21268816 is about 4611.8126588143. The cubic root of 21268816 is about 277.0646410415.

The spelling of 21268816 in words is "twenty-one million, two hundred sixty-eight thousand, eight hundred sixteen".