393921793 has 2 divisors, whose sum is σ = 393921794. Its totient is φ = 393921792.

The previous prime is 393921779. The next prime is 393921821. The reversal of 393921793 is 397129393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 386830224 + 7091569 = 19668^2 + 2663^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-393921793 is a prime.

It is not a weakly prime, because it can be changed into another prime (393921293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 196960896 + 196960897.

It is an arithmetic number, because the mean of its divisors is an integer number (196960897).

Almost surely, 2^393921793 is an apocalyptic number.

It is an amenable number.

393921793 is a deficient number, since it is larger than the sum of its proper divisors (1).

393921793 is an equidigital number, since it uses as much as digits as its factorization.

393921793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 275562, while the sum is 46.

The square root of 393921793 is about 19847.4631376405. The cubic root of 393921793 is about 733.0551840216.

The spelling of 393921793 in words is "three hundred ninety-three million, nine hundred twenty-one thousand, seven hundred ninety-three".