21715116 has 24 divisors (see below), whose sum is σ = 50755824. Its totient is φ = 7225920.

The previous prime is 21715093. The next prime is 21715153. The reversal of 21715116 is 61151712.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8106 + ... + 10446.

It is an arithmetic number, because the mean of its divisors is an integer number (2114826).

Almost surely, 2^21715116 is an apocalyptic number.

It is an amenable number.

21715116 is an abundant number, since it is smaller than the sum of its proper divisors (29040708).

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

21715116 is a wasteful number, since it uses less digits than its factorization.

21715116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3121 (or 3119 counting only the distinct ones).

The product of its digits is 420, while the sum is 24.

The square root of 21715116 is about 4659.9480683802. The cubic root of 21715116 is about 278.9891955066.

Adding to 21715116 its reverse (61151712), we get a palindrome (82866828).

The spelling of 21715116 in words is "twenty-one million, seven hundred fifteen thousand, one hundred sixteen".