31989679 has 2 divisors, whose sum is σ = 31989680. Its totient is φ = 31989678.

The previous prime is 31989677. The next prime is 31989691. The reversal of 31989679 is 97698913.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31989679 - 2¹ = 31989677 is a prime.

Together with 31989677, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31989677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15994839 + 15994840.

It is an arithmetic number, because the mean of its divisors is an integer number (15994840).

Almost surely, 2^31989679 is an apocalyptic number.

31989679 is a deficient number, since it is larger than the sum of its proper divisors (1).

31989679 is an equidigital number, since it uses as much as digits as its factorization.

31989679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 52.

The square root of 31989679 is about 5655.9419197867. The cubic root of 31989679 is about 317.4460742937.

It can be divided in two parts, 319 and 89679, that added together give a palindrome (89998).

The spelling of 31989679 in words is "thirty-one million, nine hundred eighty-nine thousand, six hundred seventy-nine".