21992960 has 120 divisors (see below), whose sum is σ = 58777488. Its totient is φ = 7884800.

The previous prime is 21992947. The next prime is 21992989. The reversal of 21992960 is 6929912.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 309725 + ... + 309795.

Almost surely, 2^21992960 is an apocalyptic number.

21992960 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 21992960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29388744).

21992960 is an abundant number, since it is smaller than the sum of its proper divisors (36784528).

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

21992960 is an equidigital number, since it uses as much as digits as its factorization.

21992960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 21992960 is about 4689.6652332549. The cubic root of 21992960 is about 280.1740414573.

The spelling of 21992960 in words is "twenty-one million, nine hundred ninety-two thousand, nine hundred sixty".