21974944 has 48 divisors (see below), whose sum is σ = 46569600. Its totient is φ = 10174464.

The previous prime is 21974941. The next prime is 21974951. The reversal of 21974944 is 44947912.

It is a junction number, because it is equal to n+sod(n) for n = 21974897 and 21974906.

It is not an unprimeable number, because it can be changed into a prime (21974941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28192 + ... + 28960.

It is an arithmetic number, because the mean of its divisors is an integer number (970200).

Almost surely, 2^21974944 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 21974944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23284800).

21974944 is an abundant number, since it is smaller than the sum of its proper divisors (24594656).

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

21974944 is a wasteful number, since it uses less digits than its factorization.

21974944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 837 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 21974944 is about 4687.7440203151. The cubic root of 21974944 is about 280.0975170537.

The spelling of 21974944 in words is "twenty-one million, nine hundred seventy-four thousand, nine hundred forty-four".