21368884 has 6 divisors (see below), whose sum is σ = 37395554. Its totient is φ = 10684440.

The previous prime is 21368861. The next prime is 21368899. The reversal of 21368884 is 48886312.

It can be written as a sum of positive squares in only one way, i.e., 19184400 + 2184484 = 4380^2 + 1478^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2671107 + ... + 2671114.

Almost surely, 2^21368884 is an apocalyptic number.

It is an amenable number.

21368884 is a deficient number, since it is larger than the sum of its proper divisors (16026670).

21368884 is a wasteful number, since it uses less digits than its factorization.

21368884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5342225 (or 5342223 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 21368884 is about 4622.6490240986. The cubic root of 21368884 is about 277.4984833399.

The spelling of 21368884 in words is "twenty-one million, three hundred sixty-eight thousand, eight hundred eighty-four".