399409919989 has 2 divisors, whose sum is σ = 399409919990. Its totient is φ = 399409919988.

The previous prime is 399409919983. The next prime is 399409920029. The reversal of 399409919989 is 989919904993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 278211941764 + 121197978225 = 527458^2 + 348135^2 .

It is a cyclic number.

It is not a de Polignac number, because 399409919989 - 2³ = 399409919981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399409919981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199704959994 + 199704959995.

It is an arithmetic number, because the mean of its divisors is an integer number (199704959995).

Almost surely, 2^399409919989 is an apocalyptic number.

It is an amenable number.

399409919989 is a deficient number, since it is larger than the sum of its proper divisors (1).

399409919989 is an equidigital number, since it uses as much as digits as its factorization.

399409919989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 459165024, while the sum is 79.

The spelling of 399409919989 in words is "three hundred ninety-nine billion, four hundred nine million, nine hundred nineteen thousand, nine hundred eighty-nine".