891131 has 4 divisors (see below), whose sum is σ = 893064. Its totient is φ = 889200.

The previous prime is 891103. The next prime is 891133. The reversal of 891131 is 131198.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 131198 = 2 ⋅65599.

It is a cyclic number.

It is not a de Polignac number, because 891131 - 2⁶ = 891067 is a prime.

It is a super-2 number, since 2×891131² = 1588228918322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 891097 and 891106.

It is not an unprimeable number, because it can be changed into a prime (891133) 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 in 3 ways as a sum of consecutive naturals, for example, 176 + ... + 1346.

It is an arithmetic number, because the mean of its divisors is an integer number (223266).

2⁸⁹¹¹³¹ is an apocalyptic number.

891131 is a deficient number, since it is larger than the sum of its proper divisors (1933).

891131 is a wasteful number, since it uses less digits than its factorization.

891131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1932.

The product of its digits is 216, while the sum is 23.

The square root of 891131 is about 943.9973516912. The cubic root of 891131 is about 96.2307455722.

The spelling of 891131 in words is "eight hundred ninety-one thousand, one hundred thirty-one".