639563963 has 2 divisors, whose sum is σ = 639563964. Its totient is φ = 639563962.

The previous prime is 639563933. The next prime is 639563989. The reversal of 639563963 is 369365936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639563963 - 2¹⁰ = 639562939 is a prime.

It is not a weakly prime, because it can be changed into another prime (639563923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319781981 + 319781982.

It is an arithmetic number, because the mean of its divisors is an integer number (319781982).

Almost surely, 2^639563963 is an apocalyptic number.

639563963 is a deficient number, since it is larger than the sum of its proper divisors (1).

639563963 is an equidigital number, since it uses as much as digits as its factorization.

639563963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2361960, while the sum is 50.

The square root of 639563963 is about 25289.6018750790. The cubic root of 639563963 is about 861.5781204580.

The spelling of 639563963 in words is "six hundred thirty-nine million, five hundred sixty-three thousand, nine hundred sixty-three".