20928880 has 120 divisors (see below), whose sum is σ = 59795280. Its totient is φ = 6773760.

The previous prime is 20928877. The next prime is 20928907. The reversal of 20928880 is 8882902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74340 + ... + 74620.

It is an arithmetic number, because the mean of its divisors is an integer number (498294).

Almost surely, 2^20928880 is an apocalyptic number.

20928880 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 20928880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29897640).

20928880 is an abundant number, since it is smaller than the sum of its proper divisors (38866400).

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

20928880 is a wasteful number, since it uses less digits than its factorization.

20928880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 37.

The square root of 20928880 is about 4574.8092856424. The cubic root of 20928880 is about 275.5806134957.

The spelling of 20928880 in words is "twenty million, nine hundred twenty-eight thousand, eight hundred eighty".