21369916 has 12 divisors (see below), whose sum is σ = 37500232. Its totient is φ = 10655568.

The previous prime is 21369911. The next prime is 21369917. The reversal of 21369916 is 61996312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21369911) 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, 5670 + ... + 8653.

Almost surely, 2^21369916 is an apocalyptic number.

It is an amenable number.

21369916 is a deficient number, since it is larger than the sum of its proper divisors (16130316).

21369916 is a wasteful number, since it uses less digits than its factorization.

21369916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14700 (or 14698 counting only the distinct ones).

The product of its digits is 17496, while the sum is 37.

The square root of 21369916 is about 4622.7606470593. The cubic root of 21369916 is about 277.5029504867.

The spelling of 21369916 in words is "twenty-one million, three hundred sixty-nine thousand, nine hundred sixteen".