31163989 has 4 divisors (see below), whose sum is σ = 31466656. Its totient is φ = 30861324.

The previous prime is 31163969. The next prime is 31164017. The reversal of 31163989 is 98936113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31163989 - 2⁷ = 31163861 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 (31163969) 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, 151179 + ... + 151384.

It is an arithmetic number, because the mean of its divisors is an integer number (7866664).

Almost surely, 2^31163989 is an apocalyptic number.

It is an amenable number.

31163989 is a deficient number, since it is larger than the sum of its proper divisors (302667).

31163989 is a wasteful number, since it uses less digits than its factorization.

31163989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302666.

The product of its digits is 34992, while the sum is 40.

The square root of 31163989 is about 5582.4715852389. The cubic root of 31163989 is about 314.6910180919.

The spelling of 31163989 in words is "thirty-one million, one hundred sixty-three thousand, nine hundred eighty-nine".