21693268 has 6 divisors (see below), whose sum is σ = 37963226. Its totient is φ = 10846632.

The previous prime is 21693253. The next prime is 21693299. The reversal of 21693268 is 86239612.

It can be written as a sum of positive squares in only one way, i.e., 17960644 + 3732624 = 4238^2 + 1932^2 .

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, 2711655 + ... + 2711662.

Almost surely, 2^21693268 is an apocalyptic number.

It is an amenable number.

21693268 is a deficient number, since it is larger than the sum of its proper divisors (16269958).

21693268 is a wasteful number, since it uses less digits than its factorization.

21693268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5423321 (or 5423319 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 21693268 is about 4657.6032463060. The cubic root of 21693268 is about 278.8955986268.

The spelling of 21693268 in words is "twenty-one million, six hundred ninety-three thousand, two hundred sixty-eight".