399239557 has 2 divisors, whose sum is σ = 399239558. Its totient is φ = 399239556.

The previous prime is 399239551. The next prime is 399239579. The reversal of 399239557 is 755932993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 239444676 + 159794881 = 15474^2 + 12641^2 .

It is a cyclic number.

It is not a de Polignac number, because 399239557 - 2⁷ = 399239429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399239551) 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, 199619778 + 199619779.

It is an arithmetic number, because the mean of its divisors is an integer number (199619779).

Almost surely, 2^399239557 is an apocalyptic number.

It is an amenable number.

399239557 is a deficient number, since it is larger than the sum of its proper divisors (1).

399239557 is an equidigital number, since it uses as much as digits as its factorization.

399239557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2296350, while the sum is 52.

The square root of 399239557 is about 19980.9798808767. The cubic root of 399239557 is about 736.3390875352.

The spelling of 399239557 in words is "three hundred ninety-nine million, two hundred thirty-nine thousand, five hundred fifty-seven".