631679 has 2 divisors, whose sum is σ = 631680. Its totient is φ = 631678.

The previous prime is 631667. The next prime is 631681. The reversal of 631679 is 976136.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631679 is a prime.

Together with 631681, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315839 + 315840.

It is an arithmetic number, because the mean of its divisors is an integer number (315840).

2⁶³¹⁶⁷⁹ is an apocalyptic number.

631679 is a deficient number, since it is larger than the sum of its proper divisors (1).

631679 is an equidigital number, since it uses as much as digits as its factorization.

631679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 32.

The square root of 631679 is about 794.7823601465. The cubic root of 631679 is about 85.8022769684.

The spelling of 631679 in words is "six hundred thirty-one thousand, six hundred seventy-nine".