639633430951 has 2 divisors, whose sum is σ = 639633430952. Its totient is φ = 639633430950.

The previous prime is 639633430913. The next prime is 639633430981. The reversal of 639633430951 is 159034336936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639633430951 - 2⁷ = 639633430823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639633430981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319816715475 + 319816715476.

It is an arithmetic number, because the mean of its divisors is an integer number (319816715476).

Almost surely, 2^639633430951 is an apocalyptic number.

639633430951 is a deficient number, since it is larger than the sum of its proper divisors (1).

639633430951 is an equidigital number, since it uses as much as digits as its factorization.

639633430951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4723920, while the sum is 52.

The spelling of 639633430951 in words is "six hundred thirty-nine billion, six hundred thirty-three million, four hundred thirty thousand, nine hundred fifty-one".