31370991 has 4 divisors (see below), whose sum is σ = 41827992. Its totient is φ = 20913992.

The previous prime is 31370981. The next prime is 31371007. The reversal of 31370991 is 19907313.

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

It is a cyclic number.

It is not a de Polignac number, because 31370991 - 2⁵ = 31370959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31370921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5228496 + ... + 5228501.

It is an arithmetic number, because the mean of its divisors is an integer number (10456998).

Almost surely, 2^31370991 is an apocalyptic number.

31370991 is a deficient number, since it is larger than the sum of its proper divisors (10457001).

31370991 is a wasteful number, since it uses less digits than its factorization.

31370991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10457000.

The product of its (nonzero) digits is 5103, while the sum is 33.

The square root of 31370991 is about 5600.9812533162. The cubic root of 31370991 is about 315.3862432641.

The spelling of 31370991 in words is "thirty-one million, three hundred seventy thousand, nine hundred ninety-one".