28540880 has 20 divisors (see below), whose sum is σ = 66357732. Its totient is φ = 11416320.

The previous prime is 28540849. The next prime is 28540921. The reversal of 28540880 is 8804582.

It can be written as a sum of positive squares in 2 ways, for example, as 4648336 + 23892544 = 2156^2 + 4888^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28540880.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178301 + ... + 178460.

Almost surely, 2^28540880 is an apocalyptic number.

28540880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28540880 is an abundant number, since it is smaller than the sum of its proper divisors (37816852).

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

28540880 is a wasteful number, since it uses less digits than its factorization.

28540880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356774 (or 356768 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 35.

The square root of 28540880 is about 5342.3665168163. The cubic root of 28540880 is about 305.6017145815.

The spelling of 28540880 in words is "twenty-eight million, five hundred forty thousand, eight hundred eighty".