631979 has 2 divisors, whose sum is σ = 631980. Its totient is φ = 631978.

The previous prime is 631937. The next prime is 631987. The reversal of 631979 is 979136.

631979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 631979 - 2⁸ = 631723 is a prime.

It is not a weakly prime, because it can be changed into another prime (631679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315989 + 315990.

It is an arithmetic number, because the mean of its divisors is an integer number (315990).

2⁶³¹⁹⁷⁹ is an apocalyptic number.

631979 is a deficient number, since it is larger than the sum of its proper divisors (1).

631979 is an equidigital number, since it uses as much as digits as its factorization.

631979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10206, while the sum is 35.

The square root of 631979 is about 794.9710686560. The cubic root of 631979 is about 85.8158580274.

The spelling of 631979 in words is "six hundred thirty-one thousand, nine hundred seventy-nine".