639806311 has 2 divisors, whose sum is σ = 639806312. Its totient is φ = 639806310.

The previous prime is 639806309. The next prime is 639806317. The reversal of 639806311 is 113608936.

639806311 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639806311 - 2¹ = 639806309 is a prime.

Together with 639806309, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639806317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319903155 + 319903156.

It is an arithmetic number, because the mean of its divisors is an integer number (319903156).

Almost surely, 2^639806311 is an apocalyptic number.

639806311 is a deficient number, since it is larger than the sum of its proper divisors (1).

639806311 is an equidigital number, since it uses as much as digits as its factorization.

639806311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 639806311 is about 25294.3928766832. The cubic root of 639806311 is about 861.6869317619.

The spelling of 639806311 in words is "six hundred thirty-nine million, eight hundred six thousand, three hundred eleven".