6399139 has 2 divisors, whose sum is σ = 6399140. Its totient is φ = 6399138.

The previous prime is 6399137. The next prime is 6399161. The reversal of 6399139 is 9319936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6399139 - 2¹ = 6399137 is a prime.

Together with 6399137, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6399137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3199569 + 3199570.

It is an arithmetic number, because the mean of its divisors is an integer number (3199570).

Almost surely, 2^6399139 is an apocalyptic number.

6399139 is a deficient number, since it is larger than the sum of its proper divisors (1).

6399139 is an equidigital number, since it uses as much as digits as its factorization.

6399139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39366, while the sum is 40.

The square root of 6399139 is about 2529.6519523444. The cubic root of 6399139 is about 185.6552271212.

The spelling of 6399139 in words is "six million, three hundred ninety-nine thousand, one hundred thirty-nine".