21944736 has 96 divisors (see below), whose sum is σ = 69854400. Its totient is φ = 6647040.

The previous prime is 21944701. The next prime is 21944759. The reversal of 21944736 is 63744912.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21944736.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8350 + ... + 10658.

It is an arithmetic number, because the mean of its divisors is an integer number (727650).

Almost surely, 2^21944736 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 21944736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34927200).

21944736 is an abundant number, since it is smaller than the sum of its proper divisors (47909664).

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

21944736 is a wasteful number, since it uses less digits than its factorization.

21944736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2339 (or 2325 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21944736 is about 4684.5208933252. The cubic root of 21944736 is about 279.9691122390.

The spelling of 21944736 in words is "twenty-one million, nine hundred forty-four thousand, seven hundred thirty-six".