285631 has 2 divisors, whose sum is σ = 285632. Its totient is φ = 285630.

The previous prime is 285629. The next prime is 285641. The reversal of 285631 is 136582.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 285631 - 2¹ = 285629 is a prime.

It is a super-2 number, since 2×285631² = 163170136322, which contains 22 as substring.

Together with 285629, it forms a pair of twin primes.

It is a d-powerful number, because it can be written as 2¹¹ + 8³ + 6⁷ + 5⁵ + 3² + 1 .

It is equal to p₂₄₈₉₂ and since 285631 and 24892 have the same sum of digits, it is a Honaker prime.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 285596 and 285605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142815 + 142816.

It is an arithmetic number, because the mean of its divisors is an integer number (142816).

2²⁸⁵⁶³¹ is an apocalyptic number.

285631 is a deficient number, since it is larger than the sum of its proper divisors (1).

285631 is an equidigital number, since it uses as much as digits as its factorization.

285631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 285631 is about 534.4445714946. Note that the first 3 decimals coincide. The cubic root of 285631 is about 65.8569752542.

The spelling of 285631 in words is "two hundred eighty-five thousand, six hundred thirty-one".