631335989 has 2 divisors, whose sum is σ = 631335990. Its totient is φ = 631335988.

The previous prime is 631335979. The next prime is 631336073. The reversal of 631335989 is 989533136.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 613552900 + 17783089 = 24770^2 + 4217^2 .

It is a cyclic number.

It is not a de Polignac number, because 631335989 - 2⁴ = 631335973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631335979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315667994 + 315667995.

It is an arithmetic number, because the mean of its divisors is an integer number (315667995).

Almost surely, 2^631335989 is an apocalyptic number.

It is an amenable number.

631335989 is a deficient number, since it is larger than the sum of its proper divisors (1).

631335989 is an equidigital number, since it uses as much as digits as its factorization.

631335989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 524880, while the sum is 47.

The square root of 631335989 is about 25126.4002395886. The cubic root of 631335989 is about 857.8674352311.

The spelling of 631335989 in words is "six hundred thirty-one million, three hundred thirty-five thousand, nine hundred eighty-nine".