287856 has 30 divisors (see below), whose sum is σ = 806000. Its totient is φ = 95904.

The previous prime is 287851. The next prime is 287857. The reversal of 287856 is 658782.

It is a super-2 number, since 2×287856² = 165722153472, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 287856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287851) by changing a digit.

287856 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 856 + ... + 1143.

2²⁸⁷⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

287856 is an abundant number, since it is smaller than the sum of its proper divisors (518144).

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

287856 is a wasteful number, since it uses less digits than its factorization.

287856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2013 (or 2004 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 287856 is about 536.5221337466. The cubic root of 287856 is about 66.0275367188.

The spelling of 287856 in words is "two hundred eighty-seven thousand, eight hundred fifty-six".