639789263 has 2 divisors, whose sum is σ = 639789264. Its totient is φ = 639789262.

The previous prime is 639789221. The next prime is 639789277. The reversal of 639789263 is 362987936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639789263 - 2¹⁴ = 639772879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639789463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319894631 + 319894632.

It is an arithmetic number, because the mean of its divisors is an integer number (319894632).

Almost surely, 2^639789263 is an apocalyptic number.

639789263 is a deficient number, since it is larger than the sum of its proper divisors (1).

639789263 is an equidigital number, since it uses as much as digits as its factorization.

639789263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 53.

The square root of 639789263 is about 25294.0558827563. The cubic root of 639789263 is about 861.6792783159.

The spelling of 639789263 in words is "six hundred thirty-nine million, seven hundred eighty-nine thousand, two hundred sixty-three".