21965120 has 56 divisors (see below), whose sum is σ = 52998624. Its totient is φ = 8669696.

The previous prime is 21965117. The next prime is 21965149. The reversal of 21965120 is 2156912.

It is a super-2 number, since 2×21965120² = 964932993228800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21965120.

It is a congruent number.

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, 26147 + ... + 26973.

It is an arithmetic number, because the mean of its divisors is an integer number (946404).

Almost surely, 2^21965120 is an apocalyptic number.

21965120 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 21965120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26499312).

21965120 is an abundant number, since it is smaller than the sum of its proper divisors (31033504).

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

21965120 is an equidigital number, since it uses as much as digits as its factorization.

21965120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 927 (or 917 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 21965120 is about 4686.6960643933. The cubic root of 21965120 is about 280.0557712035.

The spelling of 21965120 in words is "twenty-one million, nine hundred sixty-five thousand, one hundred twenty".