31679939 has 2 divisors, whose sum is σ = 31679940. Its totient is φ = 31679938.

The previous prime is 31679917. The next prime is 31679941. The reversal of 31679939 is 93997613.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31679939 is a prime.

It is a super-3 number, since 3×31679939³ (a number of 23 digits) contains 333 as substring.

Together with 31679941, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31679893 and 31679902.

It is not a weakly prime, because it can be changed into another prime (31679239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15839969 + 15839970.

It is an arithmetic number, because the mean of its divisors is an integer number (15839970).

Almost surely, 2^31679939 is an apocalyptic number.

31679939 is a deficient number, since it is larger than the sum of its proper divisors (1).

31679939 is an equidigital number, since it uses as much as digits as its factorization.

31679939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 275562, while the sum is 47.

The square root of 31679939 is about 5628.4934929340. The cubic root of 31679939 is about 316.4181926501.

The spelling of 31679939 in words is "thirty-one million, six hundred seventy-nine thousand, nine hundred thirty-nine".