399665983 has 2 divisors, whose sum is σ = 399665984. Its totient is φ = 399665982.

The previous prime is 399665953. The next prime is 399665993. The reversal of 399665983 is 389566993.

It is a strong prime.

It is an emirp because it is prime and its reverse (389566993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399665983 - 2⁹ = 399665471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399665923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199832991 + 199832992.

It is an arithmetic number, because the mean of its divisors is an integer number (199832992).

Almost surely, 2^399665983 is an apocalyptic number.

399665983 is a deficient number, since it is larger than the sum of its proper divisors (1).

399665983 is an equidigital number, since it uses as much as digits as its factorization.

399665983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9447840, while the sum is 58.

The square root of 399665983 is about 19991.6478310318. The cubic root of 399665983 is about 736.6011544243.

The spelling of 399665983 in words is "three hundred ninety-nine million, six hundred sixty-five thousand, nine hundred eighty-three".