21415868 has 12 divisors (see below), whose sum is σ = 37521120. Its totient is φ = 10695552.

The previous prime is 21415847. The next prime is 21415871. The reversal of 21415868 is 86851412.

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, 1580 + ... + 6732.

It is an arithmetic number, because the mean of its divisors is an integer number (3126760).

Almost surely, 2^21415868 is an apocalyptic number.

It is an amenable number.

21415868 is a deficient number, since it is larger than the sum of its proper divisors (16105252).

21415868 is a wasteful number, since it uses less digits than its factorization.

21415868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6196 (or 6194 counting only the distinct ones).

The product of its digits is 15360, while the sum is 35.

The square root of 21415868 is about 4627.7281683349. The cubic root of 21415868 is about 277.7017141186.

The spelling of 21415868 in words is "twenty-one million, four hundred fifteen thousand, eight hundred sixty-eight".