6404639863 has 2 divisors, whose sum is σ = 6404639864. Its totient is φ = 6404639862.

The previous prime is 6404639849. The next prime is 6404639867. The reversal of 6404639863 is 3689364046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6404639863 - 2⁵ = 6404639831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6404639867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3202319931 + 3202319932.

It is an arithmetic number, because the mean of its divisors is an integer number (3202319932).

Almost surely, 2^6404639863 is an apocalyptic number.

6404639863 is a deficient number, since it is larger than the sum of its proper divisors (1).

6404639863 is an equidigital number, since it uses as much as digits as its factorization.

6404639863 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2239488, while the sum is 49.

The square root of 6404639863 is about 80028.9938897147. The cubic root of 6404639863 is about 1857.0840987352.

The spelling of 6404639863 in words is "six billion, four hundred four million, six hundred thirty-nine thousand, eight hundred sixty-three".