639308671 has 2 divisors, whose sum is σ = 639308672. Its totient is φ = 639308670.

The previous prime is 639308651. The next prime is 639308701. The reversal of 639308671 is 176803936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639308671 - 2⁵ = 639308639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639308641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319654335 + 319654336.

It is an arithmetic number, because the mean of its divisors is an integer number (319654336).

Almost surely, 2^639308671 is an apocalyptic number.

639308671 is a deficient number, since it is larger than the sum of its proper divisors (1).

639308671 is an equidigital number, since it uses as much as digits as its factorization.

639308671 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 639308671 is about 25284.5540004169. The cubic root of 639308671 is about 861.4634677223.

The spelling of 639308671 in words is "six hundred thirty-nine million, three hundred eight thousand, six hundred seventy-one".