20989280 has 48 divisors (see below), whose sum is σ = 53406864. Its totient is φ = 7749120.

The previous prime is 20989279. The next prime is 20989313. The reversal of 20989280 is 8298902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2966 + ... + 7125.

It is an arithmetic number, because the mean of its divisors is an integer number (1112643).

Almost surely, 2^20989280 is an apocalyptic number.

20989280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20989280 is an abundant number, since it is smaller than the sum of its proper divisors (32417584).

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

20989280 is a wasteful number, since it uses less digits than its factorization.

20989280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10119 (or 10111 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 20989280 is about 4581.4058977567. The cubic root of 20989280 is about 275.8454641442.

The spelling of 20989280 in words is "twenty million, nine hundred eighty-nine thousand, two hundred eighty".