891031 has 4 divisors (see below), whose sum is σ = 895752. Its totient is φ = 886312.

The previous prime is 891017. The next prime is 891047. The reversal of 891031 is 130198.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130198 = 2 ⋅65099.

It is a cyclic number.

It is not a de Polignac number, because 891031 - 2⁵ = 890999 is a prime.

It is a super-2 number, since 2×891031² = 1587872485922, which contains 22 as substring.

It is a Duffinian number.

891031 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 890993 and 891011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891001) 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 3 ways as a sum of consecutive naturals, for example, 2065 + ... + 2458.

It is an arithmetic number, because the mean of its divisors is an integer number (223938).

2⁸⁹¹⁰³¹ is an apocalyptic number.

891031 is a deficient number, since it is larger than the sum of its proper divisors (4721).

891031 is a wasteful number, since it uses less digits than its factorization.

891031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4720.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 891031 is about 943.9443839549. The cubic root of 891031 is about 96.2271458641.

The spelling of 891031 in words is "eight hundred ninety-one thousand, thirty-one".