285115220 has 48 divisors (see below), whose sum is σ = 655405968. Its totient is φ = 103541760.

The previous prime is 285115213. The next prime is 285115247. The reversal of 285115220 is 22511582.

It can be written as a sum of positive squares in 8 ways, for example, as 81938704 + 203176516 = 9052^2 + 14254^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 285115220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6872 + ... + 24848.

It is an arithmetic number, because the mean of its divisors is an integer number (13654291).

Almost surely, 2^285115220 is an apocalyptic number.

285115220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 285115220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327702984).

285115220 is an abundant number, since it is smaller than the sum of its proper divisors (370290748).

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

285115220 is a wasteful number, since it uses less digits than its factorization.

285115220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18060 (or 18058 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 285115220 is about 16885.3551931844. The cubic root of 285115220 is about 658.1731081884.

The spelling of 285115220 in words is "two hundred eighty-five million, one hundred fifteen thousand, two hundred twenty".