31979945 has 8 divisors (see below), whose sum is σ = 40395840. Its totient is φ = 24237360.

The previous prime is 31979929. The next prime is 31979963. The reversal of 31979945 is 54997913.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31979945 - 2⁴ = 31979929 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31979945.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168221 + ... + 168410.

It is an arithmetic number, because the mean of its divisors is an integer number (5049480).

Almost surely, 2^31979945 is an apocalyptic number.

It is an amenable number.

31979945 is a deficient number, since it is larger than the sum of its proper divisors (8415895).

31979945 is a wasteful number, since it uses less digits than its factorization.

31979945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336655.

The product of its digits is 306180, while the sum is 47.

The square root of 31979945 is about 5655.0813433584. The cubic root of 31979945 is about 317.4138729332.

The spelling of 31979945 in words is "thirty-one million, nine hundred seventy-nine thousand, nine hundred forty-five".