20918128 has 40 divisors (see below), whose sum is σ = 50532480. Its totient is φ = 8149440.

The previous prime is 20918113. The next prime is 20918189. The reversal of 20918128 is 82181902.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20918128.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7258 + ... + 9721.

It is an arithmetic number, because the mean of its divisors is an integer number (1263312).

Almost surely, 2^20918128 is an apocalyptic number.

20918128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20918128 is an abundant number, since it is smaller than the sum of its proper divisors (29614352).

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

20918128 is a wasteful number, since it uses less digits than its factorization.

20918128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17005 (or 16999 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 20918128 is about 4573.6340037218. The cubic root of 20918128 is about 275.5334131628.

The spelling of 20918128 in words is "twenty million, nine hundred eighteen thousand, one hundred twenty-eight".