31160991 has 4 divisors (see below), whose sum is σ = 41547992. Its totient is φ = 20773992.

The previous prime is 31160981. The next prime is 31161019. The reversal of 31160991 is 19906113.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-31160991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31160911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5193496 + ... + 5193501.

It is an arithmetic number, because the mean of its divisors is an integer number (10386998).

Almost surely, 2^31160991 is an apocalyptic number.

31160991 is a deficient number, since it is larger than the sum of its proper divisors (10387001).

31160991 is a wasteful number, since it uses less digits than its factorization.

31160991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10387000.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 31160991 is about 5582.2030597247. The cubic root of 31160991 is about 314.6809265947.

The spelling of 31160991 in words is "thirty-one million, one hundred sixty thousand, nine hundred ninety-one".