399999317 has 2 divisors, whose sum is σ = 399999318. Its totient is φ = 399999316.

The previous prime is 399999247. The next prime is 399999323. The reversal of 399999317 is 713999993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 390102001 + 9897316 = 19751^2 + 3146^2 .

It is a cyclic number.

It is not a de Polignac number, because 399999317 - 2¹⁰ = 399998293 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399999377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199999658 + 199999659.

It is an arithmetic number, because the mean of its divisors is an integer number (199999659).

Almost surely, 2^399999317 is an apocalyptic number.

It is an amenable number.

399999317 is a deficient number, since it is larger than the sum of its proper divisors (1).

399999317 is an equidigital number, since it uses as much as digits as its factorization.

399999317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3720087, while the sum is 59.

The square root of 399999317 is about 19999.9829249927. The cubic root of 399999317 is about 736.8058803623.

The spelling of 399999317 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, three hundred seventeen".