285731 has 2 divisors, whose sum is σ = 285732. Its totient is φ = 285730.

The previous prime is 285721. The next prime is 285749. The reversal of 285731 is 137582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 285731 - 2⁶ = 285667 is a prime.

It is a super-2 number, since 2×285731² = 163284408722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 285731.

It is not a weakly prime, because it can be changed into another prime (285721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142865 + 142866.

It is an arithmetic number, because the mean of its divisors is an integer number (142866).

2²⁸⁵⁷³¹ is an apocalyptic number.

285731 is a deficient number, since it is larger than the sum of its proper divisors (1).

285731 is an equidigital number, since it uses as much as digits as its factorization.

285731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 285731 is about 534.5381183788. The cubic root of 285731 is about 65.8646599116.

It can be divided in two parts, 285 and 731, that multiplied together give a triangular number (208335 = T₆₄₅).

The spelling of 285731 in words is "two hundred eighty-five thousand, seven hundred thirty-one".