399444293 has 2 divisors, whose sum is σ = 399444294. Its totient is φ = 399444292.

The previous prime is 399444281. The next prime is 399444299. The reversal of 399444293 is 392444993.

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., 397683364 + 1760929 = 19942^2 + 1327^2 .

It is an emirp because it is prime and its reverse (392444993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399444293 - 2¹⁴ = 399427909 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399444299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199722146 + 199722147.

It is an arithmetic number, because the mean of its divisors is an integer number (199722147).

Almost surely, 2^399444293 is an apocalyptic number.

It is an amenable number.

399444293 is a deficient number, since it is larger than the sum of its proper divisors (1).

399444293 is an equidigital number, since it uses as much as digits as its factorization.

399444293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 47.

The square root of 399444293 is about 19986.1024964849. The cubic root of 399444293 is about 736.4649345814.

The spelling of 399444293 in words is "three hundred ninety-nine million, four hundred forty-four thousand, two hundred ninety-three".