21944484 has 72 divisors (see below), whose sum is σ = 61326720. Its totient is φ = 6580992.

The previous prime is 21944477. The next prime is 21944521. The reversal of 21944484 is 48444912.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 13297 + ... + 14855.

It is an arithmetic number, because the mean of its divisors is an integer number (851760).

Almost surely, 2^21944484 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 21944484, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30663360).

21944484 is an abundant number, since it is smaller than the sum of its proper divisors (39382236).

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

21944484 is a wasteful number, since it uses less digits than its factorization.

21944484 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609 (or 1604 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 21944484 is about 4684.4939961537. The cubic root of 21944484 is about 279.9680405700.

The spelling of 21944484 in words is "twenty-one million, nine hundred forty-four thousand, four hundred eighty-four".