21716616 has 96 divisors (see below), whose sum is σ = 60122880. Its totient is φ = 6528000.

The previous prime is 21716609. The next prime is 21716627. The reversal of 21716616 is 61661712.

It is a super-2 number, since 2×21716616² = 943222820982912, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 214966 + ... + 215066.

It is an arithmetic number, because the mean of its divisors is an integer number (626280).

Almost surely, 2^21716616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21716616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30061440).

21716616 is an abundant number, since it is smaller than the sum of its proper divisors (38406264).

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

21716616 is a wasteful number, since it uses less digits than its factorization.

21716616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 154 counting only the distinct ones).

The product of its digits is 3024, while the sum is 30.

The square root of 21716616 is about 4660.1090116005. The cubic root of 21716616 is about 278.9956192064.

The spelling of 21716616 in words is "twenty-one million, seven hundred sixteen thousand, six hundred sixteen".