21920580 has 72 divisors (see below), whose sum is σ = 72543744. Its totient is φ = 5313600.

The previous prime is 21920573. The next prime is 21920621. The reversal of 21920580 is 8502912.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

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 23 ways as a sum of consecutive naturals, for example, 3556 + ... + 7515.

It is an arithmetic number, because the mean of its divisors is an integer number (1007552).

Almost surely, 2^21920580 is an apocalyptic number.

21920580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21920580 is an abundant number, since it is smaller than the sum of its proper divisors (50623164).

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

21920580 is a wasteful number, since it uses less digits than its factorization.

21920580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11097 (or 11092 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 21920580 is about 4681.9419048083. The cubic root of 21920580 is about 279.8663477786.

It can be divided in two parts, 21920 and 580, that added together give a square (22500 = 150²).

The spelling of 21920580 in words is "twenty-one million, nine hundred twenty thousand, five hundred eighty".