21582880 has 48 divisors (see below), whose sum is σ = 55629504. Its totient is φ = 7847680.

The previous prime is 21582871. The next prime is 21582881. The reversal of 21582880 is 8828512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21582881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4372 + ... + 7891.

It is an arithmetic number, because the mean of its divisors is an integer number (1158948).

Almost surely, 2^21582880 is an apocalyptic number.

21582880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21582880 is an abundant number, since it is smaller than the sum of its proper divisors (34046624).

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

21582880 is a wasteful number, since it uses less digits than its factorization.

21582880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12289 (or 12281 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 34.

The square root of 21582880 is about 4645.7378316044. The cubic root of 21582880 is about 278.4217327906.

The spelling of 21582880 in words is "twenty-one million, five hundred eighty-two thousand, eight hundred eighty".