631667917 has 2 divisors, whose sum is σ = 631667918. Its totient is φ = 631667916.

The previous prime is 631667899. The next prime is 631667987. The reversal of 631667917 is 719766136.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 484264036 + 147403881 = 22006^2 + 12141^2 .

It is a cyclic number.

It is not a de Polignac number, because 631667917 - 2⁷ = 631667789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631667987) by changing a digit.

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 as a sum of consecutive naturals, namely, 315833958 + 315833959.

It is an arithmetic number, because the mean of its divisors is an integer number (315833959).

Almost surely, 2^631667917 is an apocalyptic number.

It is an amenable number.

631667917 is a deficient number, since it is larger than the sum of its proper divisors (1).

631667917 is an equidigital number, since it uses as much as digits as its factorization.

631667917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 46.

The square root of 631667917 is about 25133.0045358688. The cubic root of 631667917 is about 858.0177515648.

The spelling of 631667917 in words is "six hundred thirty-one million, six hundred sixty-seven thousand, nine hundred seventeen".