639372859 has 2 divisors, whose sum is σ = 639372860. Its totient is φ = 639372858.

The previous prime is 639372847. The next prime is 639372863. The reversal of 639372859 is 958273936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639372859 - 2⁵ = 639372827 is a prime.

It is not a weakly prime, because it can be changed into another prime (639372869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319686429 + 319686430.

It is an arithmetic number, because the mean of its divisors is an integer number (319686430).

Almost surely, 2^639372859 is an apocalyptic number.

639372859 is a deficient number, since it is larger than the sum of its proper divisors (1).

639372859 is an equidigital number, since it uses as much as digits as its factorization.

639372859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2449440, while the sum is 52.

The square root of 639372859 is about 25285.8232810403. The cubic root of 639372859 is about 861.4922977012.

The spelling of 639372859 in words is "six hundred thirty-nine million, three hundred seventy-two thousand, eight hundred fifty-nine".