399699331 has 2 divisors, whose sum is σ = 399699332. Its totient is φ = 399699330.

The previous prime is 399699323. The next prime is 399699347. The reversal of 399699331 is 133996993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399699331 - 2³ = 399699323 is a prime.

It is a super-2 number, since 2×399699331² = 319519110403695122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (399699361) 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, 199849665 + 199849666.

It is an arithmetic number, because the mean of its divisors is an integer number (199849666).

Almost surely, 2^399699331 is an apocalyptic number.

399699331 is a deficient number, since it is larger than the sum of its proper divisors (1).

399699331 is an equidigital number, since it uses as much as digits as its factorization.

399699331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1062882, while the sum is 52.

The square root of 399699331 is about 19992.4818619400. The cubic root of 399699331 is about 736.6216411083.

The spelling of 399699331 in words is "three hundred ninety-nine million, six hundred ninety-nine thousand, three hundred thirty-one".