631666733609 has 2 divisors, whose sum is σ = 631666733610. Its totient is φ = 631666733608.

The previous prime is 631666733567. The next prime is 631666733623. The reversal of 631666733609 is 906337666136.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 549484177984 + 82182555625 = 741272^2 + 286675^2 .

It is a cyclic number.

It is not a de Polignac number, because 631666733609 - 2²⁰ = 631665685033 is a prime.

It is not a weakly prime, because it can be changed into another prime (631666733629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315833366804 + 315833366805.

It is an arithmetic number, because the mean of its divisors is an integer number (315833366805).

Almost surely, 2^631666733609 is an apocalyptic number.

It is an amenable number.

631666733609 is a deficient number, since it is larger than the sum of its proper divisors (1).

631666733609 is an equidigital number, since it uses as much as digits as its factorization.

631666733609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13226976, while the sum is 56.

The spelling of 631666733609 in words is "six hundred thirty-one billion, six hundred sixty-six million, seven hundred thirty-three thousand, six hundred nine".