21580992 has 140 divisors (see below), whose sum is σ = 67123056. Its totient is φ = 6842880.

The previous prime is 21580967. The next prime is 21581003. The reversal of 21580992 is 29908512.

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

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 119142 + ... + 119322.

Almost surely, 2^21580992 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 21580992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33561528).

21580992 is an abundant number, since it is smaller than the sum of its proper divisors (45542064).

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

21580992 is a wasteful number, since it uses less digits than its factorization.

21580992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 21580992 is about 4645.5346301583. The cubic root of 21580992 is about 278.4136140786.

The spelling of 21580992 in words is "twenty-one million, five hundred eighty thousand, nine hundred ninety-two".