399699889 has 2 divisors, whose sum is σ = 399699890. Its totient is φ = 399699888.

The previous prime is 399699887. The next prime is 399699913. The reversal of 399699889 is 988996993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202578289 + 197121600 = 14233^2 + 14040^2 .

It is an emirp because it is prime and its reverse (988996993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399699889 - 2¹ = 399699887 is a prime.

It is a super-2 number, since 2×399699889² = 319520002533224642, which contains 22 as substring.

Together with 399699887, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (399699887) 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, 199849944 + 199849945.

It is an arithmetic number, because the mean of its divisors is an integer number (199849945).

Almost surely, 2^399699889 is an apocalyptic number.

It is an amenable number.

399699889 is a deficient number, since it is larger than the sum of its proper divisors (1).

399699889 is an equidigital number, since it uses as much as digits as its factorization.

399699889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68024448, while the sum is 70.

The square root of 399699889 is about 19992.4958171810. The cubic root of 399699889 is about 736.6219838949.

The spelling of 399699889 in words is "three hundred ninety-nine million, six hundred ninety-nine thousand, eight hundred eighty-nine".