393438641 has 2 divisors, whose sum is σ = 393438642. Its totient is φ = 393438640.

The previous prime is 393438631. The next prime is 393438671. The reversal of 393438641 is 146834393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 222875041 + 170563600 = 14929^2 + 13060^2 .

It is an emirp because it is prime and its reverse (146834393) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 393438641 - 2²² = 389244337 is a prime.

It is not a weakly prime, because it can be changed into another prime (393438631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 196719320 + 196719321.

It is an arithmetic number, because the mean of its divisors is an integer number (196719321).

Almost surely, 2^393438641 is an apocalyptic number.

It is an amenable number.

393438641 is a deficient number, since it is larger than the sum of its proper divisors (1).

393438641 is an equidigital number, since it uses as much as digits as its factorization.

393438641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 41.

The square root of 393438641 is about 19835.2877720491. The cubic root of 393438641 is about 732.7553597207.

The spelling of 393438641 in words is "three hundred ninety-three million, four hundred thirty-eight thousand, six hundred forty-one".