28190880 has 72 divisors (see below), whose sum is σ = 96206292. Its totient is φ = 7517184.

The previous prime is 28190863. The next prime is 28190881. The reversal of 28190880 is 8809182.

It can be written as a sum of positive squares in 2 ways, for example, as 26998416 + 1192464 = 5196^2 + 1092^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28190881) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8349 + ... + 11228.

Almost surely, 2^28190880 is an apocalyptic number.

28190880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28190880 is an abundant number, since it is smaller than the sum of its proper divisors (68015412).

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

28190880 is a wasteful number, since it uses less digits than its factorization.

28190880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19598 (or 19587 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 28190880 is about 5309.5084518249. The cubic root of 28190880 is about 304.3473637852.

The spelling of 28190880 in words is "twenty-eight million, one hundred ninety thousand, eight hundred eighty".