21158708 has 12 divisors (see below), whose sum is σ = 37320192. Its totient is φ = 10495800.

The previous prime is 21158701. The next prime is 21158729. The reversal of 21158708 is 80785112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20318 + ... + 21333.

It is an arithmetic number, because the mean of its divisors is an integer number (3110016).

Almost surely, 2^21158708 is an apocalyptic number.

It is an amenable number.

21158708 is a deficient number, since it is larger than the sum of its proper divisors (16161484).

21158708 is a wasteful number, since it uses less digits than its factorization.

21158708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41782 (or 41780 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 21158708 is about 4599.8595630736. The cubic root of 21158708 is about 276.5856952446.

The spelling of 21158708 in words is "twenty-one million, one hundred fifty-eight thousand, seven hundred eight".