631566961 has 2 divisors, whose sum is σ = 631566962. Its totient is φ = 631566960.

The previous prime is 631566919. The next prime is 631566967. The reversal of 631566961 is 169665136.

631566961 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 can be written as a sum of positive squares in only one way, i.e., 502880625 + 128686336 = 22425^2 + 11344^2 .

It is a cyclic number.

It is not a de Polignac number, because 631566961 - 2⁷ = 631566833 is a prime.

It is not a weakly prime, because it can be changed into another prime (631566967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315783480 + 315783481.

It is an arithmetic number, because the mean of its divisors is an integer number (315783481).

Almost surely, 2^631566961 is an apocalyptic number.

It is an amenable number.

631566961 is a deficient number, since it is larger than the sum of its proper divisors (1).

631566961 is an equidigital number, since it uses as much as digits as its factorization.

631566961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 174960, while the sum is 43.

The square root of 631566961 is about 25130.9960208504. The cubic root of 631566961 is about 857.9720383807.

The spelling of 631566961 in words is "six hundred thirty-one million, five hundred sixty-six thousand, nine hundred sixty-one".