21616896 has 72 divisors (see below), whose sum is σ = 65767744. Its totient is φ = 6174720.

The previous prime is 21616891. The next prime is 21616909. The reversal of 21616896 is 69861612.

It is not an unprimeable number, because it can be changed into a prime (21616891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3366 + ... + 7386.

Almost surely, 2^21616896 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 21616896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32883872).

21616896 is an abundant number, since it is smaller than the sum of its proper divisors (44150848).

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

21616896 is an equidigital number, since it uses as much as digits as its factorization.

21616896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4047 (or 4033 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 21616896 is about 4649.3973803064. The cubic root of 21616896 is about 278.5679261699.

The spelling of 21616896 in words is "twenty-one million, six hundred sixteen thousand, eight hundred ninety-six".