394379813 has 2 divisors, whose sum is σ = 394379814. Its totient is φ = 394379812.

The previous prime is 394379801. The next prime is 394379897. The reversal of 394379813 is 318973493.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 393546244 + 833569 = 19838^2 + 913^2 .

It is an emirp because it is prime and its reverse (318973493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 394379813 - 2¹⁴ = 394363429 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394370813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197189906 + 197189907.

It is an arithmetic number, because the mean of its divisors is an integer number (197189907).

Almost surely, 2^394379813 is an apocalyptic number.

It is an amenable number.

394379813 is a deficient number, since it is larger than the sum of its proper divisors (1).

394379813 is an equidigital number, since it uses as much as digits as its factorization.

394379813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 47.

The square root of 394379813 is about 19858.9982879298. The cubic root of 394379813 is about 733.3391861562.

The spelling of 394379813 in words is "three hundred ninety-four million, three hundred seventy-nine thousand, eight hundred thirteen".