28398880 has 24 divisors (see below), whose sum is σ = 67092732. Its totient is φ = 11359488.

The previous prime is 28398847. The next prime is 28398889. The reversal of 28398880 is 8889382.

It can be written as a sum of positive squares in 2 ways, for example, as 23853456 + 4545424 = 4884^2 + 2132^2 .

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28398880.

It is not an unprimeable number, because it can be changed into a prime (28398889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88587 + ... + 88906.

Almost surely, 2^28398880 is an apocalyptic number.

28398880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28398880 is an abundant number, since it is smaller than the sum of its proper divisors (38693852).

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

28398880 is a wasteful number, since it uses less digits than its factorization.

28398880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177508 (or 177500 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 46.

The square root of 28398880 is about 5329.0599546261. The cubic root of 28398880 is about 305.0940496486.

The spelling of 28398880 in words is "twenty-eight million, three hundred ninety-eight thousand, eight hundred eighty".