28505808 has 30 divisors (see below), whose sum is σ = 79777074. Its totient is φ = 9501888.

The previous prime is 28505803. The next prime is 28505857. The reversal of 28505808 is 80850582.

28505808 is a `hidden beast` number, since 28 + 50 + 580 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20142144 + 8363664 = 4488^2 + 2892^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28505801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 98835 + ... + 99122.

Almost surely, 2^28505808 is an apocalyptic number.

It is an amenable number.

28505808 is an abundant number, since it is smaller than the sum of its proper divisors (51271266).

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

28505808 is a wasteful number, since it uses less digits than its factorization.

28505808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197971 (or 197962 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 36.

The square root of 28505808 is about 5339.0830673441. The cubic root of 28505808 is about 305.4764853598.

The spelling of 28505808 in words is "twenty-eight million, five hundred five thousand, eight hundred eight".