21315708 has 36 divisors (see below), whose sum is σ = 54626208. Its totient is φ = 7007040.

The previous prime is 21315689. The next prime is 21315709. The reversal of 21315708 is 80751312.

It is a tau number, because it is divible by the number of its divisors (36).

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1428 + ... + 6683.

Almost surely, 2^21315708 is an apocalyptic number.

It is an amenable number.

21315708 is an abundant number, since it is smaller than the sum of its proper divisors (33310500).

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

21315708 is a wasteful number, since it uses less digits than its factorization.

21315708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8194 (or 8189 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 21315708 is about 4616.8937609609. The cubic root of 21315708 is about 277.2681091736.

The spelling of 21315708 in words is "twenty-one million, three hundred fifteen thousand, seven hundred eight".