285131808 has 72 divisors (see below), whose sum is σ = 873227628. Its totient is φ = 87731712.

The previous prime is 285131807. The next prime is 285131813. The reversal of 285131808 is 808131582.

It can be written as a sum of positive squares in 2 ways, for example, as 242985744 + 42146064 = 15588^2 + 6492^2 .

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 (285131807) 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, 34335 + ... + 41822.

Almost surely, 2^285131808 is an apocalyptic number.

It is an amenable number.

285131808 is an abundant number, since it is smaller than the sum of its proper divisors (588095820).

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

285131808 is a wasteful number, since it uses less digits than its factorization.

285131808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76186 (or 76175 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 285131808 is about 16885.8463809191. The cubic root of 285131808 is about 658.1858721087.

The spelling of 285131808 in words is "two hundred eighty-five million, one hundred thirty-one thousand, eight hundred eight".