31979918 has 8 divisors (see below), whose sum is σ = 49140000. Its totient is φ = 15599920.

The previous prime is 31979903. The next prime is 31979923. The reversal of 31979918 is 81997913.

It is a happy number.

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

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 194918 + ... + 195081.

It is an arithmetic number, because the mean of its divisors is an integer number (6142500).

Almost surely, 2^31979918 is an apocalyptic number.

31979918 is a deficient number, since it is larger than the sum of its proper divisors (17160082).

31979918 is a wasteful number, since it uses less digits than its factorization.

31979918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390042.

The product of its digits is 122472, while the sum is 47.

The square root of 31979918 is about 5655.0789561243. The cubic root of 31979918 is about 317.4137836045.

The spelling of 31979918 in words is "thirty-one million, nine hundred seventy-nine thousand, nine hundred eighteen".