21964868 has 6 divisors (see below), whose sum is σ = 38438526. Its totient is φ = 10982432.

The previous prime is 21964837. The next prime is 21964903. The reversal of 21964868 is 86846912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 13191424 + 8773444 = 3632^2 + 2962^2 .

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, 2745605 + ... + 2745612.

It is an arithmetic number, because the mean of its divisors is an integer number (6406421).

Almost surely, 2^21964868 is an apocalyptic number.

It is an amenable number.

21964868 is a deficient number, since it is larger than the sum of its proper divisors (16473658).

21964868 is a wasteful number, since it uses less digits than its factorization.

21964868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5491221 (or 5491219 counting only the distinct ones).

The product of its digits is 165888, while the sum is 44.

The square root of 21964868 is about 4686.6691797053. The cubic root of 21964868 is about 280.0547001975.

The spelling of 21964868 in words is "twenty-one million, nine hundred sixty-four thousand, eight hundred sixty-eight".