891531 has 12 divisors (see below), whose sum is σ = 1363752. Its totient is φ = 559296.

The previous prime is 891523. The next prime is 891551. The reversal of 891531 is 135198.

It is not a de Polignac number, because 891531 - 2³ = 891523 is a prime.

It is a super-2 number, since 2×891531² = 1589655047922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 891495 and 891504.

It is not an unprimeable number, because it can be changed into a prime (891521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2761 + ... + 3066.

It is an arithmetic number, because the mean of its divisors is an integer number (113646).

2⁸⁹¹⁵³¹ is an apocalyptic number.

891531 is a deficient number, since it is larger than the sum of its proper divisors (472221).

891531 is a wasteful number, since it uses less digits than its factorization.

891531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5850 (or 5847 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 891531 is about 944.2091929228. The cubic root of 891531 is about 96.2451417124.

The spelling of 891531 in words is "eight hundred ninety-one thousand, five hundred thirty-one".