21944560 has 60 divisors (see below), whose sum is σ = 56105784. Its totient is φ = 7976320.

The previous prime is 21944551. The next prime is 21944579. The reversal of 21944560 is 6544912.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 8547 + ... + 10813.

Almost surely, 2^21944560 is an apocalyptic number.

21944560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21944560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28052892).

21944560 is an abundant number, since it is smaller than the sum of its proper divisors (34161224).

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

21944560 is a wasteful number, since it uses less digits than its factorization.

21944560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302 (or 2285 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21944560 is about 4684.5021080153. The cubic root of 21944560 is about 279.9683637726.

The spelling of 21944560 in words is "twenty-one million, nine hundred forty-four thousand, five hundred sixty".