399808442489 has 2 divisors, whose sum is σ = 399808442490. Its totient is φ = 399808442488.

The previous prime is 399808442479. The next prime is 399808442491. The reversal of 399808442489 is 984244808993.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211705813225 + 188102629264 = 460115^2 + 433708^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399808442489 is a prime.

Together with 399808442491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399808442459) 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, 199904221244 + 199904221245.

It is an arithmetic number, because the mean of its divisors is an integer number (199904221245).

Almost surely, 2^399808442489 is an apocalyptic number.

It is an amenable number.

399808442489 is a deficient number, since it is larger than the sum of its proper divisors (1).

399808442489 is an equidigital number, since it uses as much as digits as its factorization.

399808442489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 143327232, while the sum is 68.

The spelling of 399808442489 in words is "three hundred ninety-nine billion, eight hundred eight million, four hundred forty-two thousand, four hundred eighty-nine".