21918896 has 40 divisors (see below), whose sum is σ = 44476320. Its totient is φ = 10450944.

The previous prime is 21918881. The next prime is 21919003. The reversal of 21918896 is 69881912.

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, 44765 + ... + 45251.

It is an arithmetic number, because the mean of its divisors is an integer number (1111908).

Almost surely, 2^21918896 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 21918896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22238160).

21918896 is an abundant number, since it is smaller than the sum of its proper divisors (22557424).

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

21918896 is a wasteful number, since it uses less digits than its factorization.

21918896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 615 counting only the distinct ones).

The product of its digits is 62208, while the sum is 44.

The square root of 21918896 is about 4681.7620614465. The cubic root of 21918896 is about 279.8591808910.

The spelling of 21918896 in words is "twenty-one million, nine hundred eighteen thousand, eight hundred ninety-six".