90831 has 16 divisors (see below), whose sum is σ = 139104. Its totient is φ = 52224.

The previous prime is 90823. The next prime is 90833. The reversal of 90831 is 13809.

It is not a de Polignac number, because 90831 - 2³ = 90823 is a prime.

It is a super-2 number, since 2×90831² = 16500541122, which contains 22 as substring.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 90798 and 90807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 595 + ... + 731.

It is an arithmetic number, because the mean of its divisors is an integer number (8694).

2⁹⁰⁸³¹ is an apocalyptic number.

90831 is a deficient number, since it is larger than the sum of its proper divisors (48273).

90831 is a wasteful number, since it uses less digits than its factorization.

90831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 90831 is about 301.3818176334. The cubic root of 90831 is about 44.9515527985.

It can be divided in two parts, 908 and 31, that added together give a palindrome (939).

The spelling of 90831 in words is "ninety thousand, eight hundred thirty-one".