399384943 has 2 divisors, whose sum is σ = 399384944. Its totient is φ = 399384942.

The previous prime is 399384941. The next prime is 399385001. The reversal of 399384943 is 349483993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399384943 - 2¹ = 399384941 is a prime.

It is a super-2 number, since 2×399384943² = 319016665390226498, which contains 22 as substring.

Together with 399384941, 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 (399384941) 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, 199692471 + 199692472.

It is an arithmetic number, because the mean of its divisors is an integer number (199692472).

Almost surely, 2^399384943 is an apocalyptic number.

399384943 is a deficient number, since it is larger than the sum of its proper divisors (1).

399384943 is an equidigital number, since it uses as much as digits as its factorization.

399384943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2519424, while the sum is 52.

The square root of 399384943 is about 19984.6176595901. The cubic root of 399384943 is about 736.4284577730.

The spelling of 399384943 in words is "three hundred ninety-nine million, three hundred eighty-four thousand, nine hundred forty-three".