639643445963 has 2 divisors, whose sum is σ = 639643445964. Its totient is φ = 639643445962.

The previous prime is 639643445933. The next prime is 639643445977. The reversal of 639643445963 is 369544346936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639643445963 - 2²² = 639639251659 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 639643445896 and 639643445905.

It is not a weakly prime, because it can be changed into another prime (639643445933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319821722981 + 319821722982.

It is an arithmetic number, because the mean of its divisors is an integer number (319821722982).

Almost surely, 2^639643445963 is an apocalyptic number.

639643445963 is a deficient number, since it is larger than the sum of its proper divisors (1).

639643445963 is an equidigital number, since it uses as much as digits as its factorization.

639643445963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151165440, while the sum is 62.

The spelling of 639643445963 in words is "six hundred thirty-nine billion, six hundred forty-three million, four hundred forty-five thousand, nine hundred sixty-three".