639791963 has 2 divisors, whose sum is σ = 639791964. Its totient is φ = 639791962.

The previous prime is 639791953. The next prime is 639792029. The reversal of 639791963 is 369197936.

It is a happy number.

639791963 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639791963 - 2⁶ = 639791899 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (639791903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319895981 + 319895982.

It is an arithmetic number, because the mean of its divisors is an integer number (319895982).

Almost surely, 2^639791963 is an apocalyptic number.

639791963 is a deficient number, since it is larger than the sum of its proper divisors (1).

639791963 is an equidigital number, since it uses as much as digits as its factorization.

639791963 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1653372, while the sum is 53.

The square root of 639791963 is about 25294.1092549234. The cubic root of 639791963 is about 861.6804904498.

The spelling of 639791963 in words is "six hundred thirty-nine million, seven hundred ninety-one thousand, nine hundred sixty-three".