21920760 has 64 divisors (see below), whose sum is σ = 73072800. Its totient is φ = 5845248.

The previous prime is 21920749. The next prime is 21920791. The reversal of 21920760 is 6702912.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9069 + ... + 11228.

Almost surely, 2^21920760 is an apocalyptic number.

21920760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21920760 is an abundant number, since it is smaller than the sum of its proper divisors (51152040).

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

21920760 is a wasteful number, since it uses less digits than its factorization.

21920760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20317 (or 20307 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21920760 is about 4681.9611275618. The cubic root of 21920760 is about 279.8671138138.

The spelling of 21920760 in words is "twenty-one million, nine hundred twenty thousand, seven hundred sixty".