21700916 has 12 divisors (see below), whose sum is σ = 38100132. Its totient is φ = 10815168.

The previous prime is 21700901. The next prime is 21700949. The reversal of 21700916 is 61900712.

It can be written as a sum of positive squares in 2 ways, for example, as 504100 + 21196816 = 710^2 + 4604^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

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, 7415 + ... + 9918.

It is an arithmetic number, because the mean of its divisors is an integer number (3175011).

Almost surely, 2^21700916 is an apocalyptic number.

It is an amenable number.

21700916 is a deficient number, since it is larger than the sum of its proper divisors (16399216).

21700916 is a wasteful number, since it uses less digits than its factorization.

21700916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17650 (or 17648 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 26.

The square root of 21700916 is about 4658.4241970864. The cubic root of 21700916 is about 278.9283698215.

The spelling of 21700916 in words is "twenty-one million, seven hundred thousand, nine hundred sixteen".