631636961 has 2 divisors, whose sum is σ = 631636962. Its totient is φ = 631636960.

The previous prime is 631636927. The next prime is 631636979. The reversal of 631636961 is 169636136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 518427361 + 113209600 = 22769^2 + 10640^2 .

It is a cyclic number.

It is not a de Polignac number, because 631636961 - 2⁶ = 631636897 is a prime.

It is not a weakly prime, because it can be changed into another prime (631636991) 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, 315818480 + 315818481.

It is an arithmetic number, because the mean of its divisors is an integer number (315818481).

Almost surely, 2^631636961 is an apocalyptic number.

It is an amenable number.

631636961 is a deficient number, since it is larger than the sum of its proper divisors (1).

631636961 is an equidigital number, since it uses as much as digits as its factorization.

631636961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 41.

The square root of 631636961 is about 25132.3886847231. The cubic root of 631636961 is about 858.0037351116.

The spelling of 631636961 in words is "six hundred thirty-one million, six hundred thirty-six thousand, nine hundred sixty-one".