21158694 has 12 divisors (see below), whose sum is σ = 45843876. Its totient is φ = 7052892.

The previous prime is 21158677. The next prime is 21158701. The reversal of 21158694 is 49685112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 587724 + ... + 587759.

It is an arithmetic number, because the mean of its divisors is an integer number (3820323).

Almost surely, 2^21158694 is an apocalyptic number.

21158694 is an abundant number, since it is smaller than the sum of its proper divisors (24685182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21158694 is a wasteful number, since it uses less digits than its factorization.

21158694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1175491 (or 1175488 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 21158694 is about 4599.8580412878. The cubic root of 21158694 is about 276.5856342421.

The spelling of 21158694 in words is "twenty-one million, one hundred fifty-eight thousand, six hundred ninety-four".