397857717 has 8 divisors (see below), whose sum is σ = 589418880. Its totient is φ = 265238460.

The previous prime is 397857653. The next prime is 397857731. The reversal of 397857717 is 717758793.

It is a happy number.

It is not a de Polignac number, because 397857717 - 2⁶ = 397857653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397857737) 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 in 7 ways as a sum of consecutive naturals, for example, 7367709 + ... + 7367762.

It is an arithmetic number, because the mean of its divisors is an integer number (73677360).

Almost surely, 2^397857717 is an apocalyptic number.

It is an amenable number.

397857717 is a deficient number, since it is larger than the sum of its proper divisors (191561163).

397857717 is a wasteful number, since it uses less digits than its factorization.

397857717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14735480 (or 14735474 counting only the distinct ones).

The product of its digits is 2593080, while the sum is 54.

The square root of 397857717 is about 19946.3710233215. The cubic root of 397857717 is about 735.4885714565.

The spelling of 397857717 in words is "three hundred ninety-seven million, eight hundred fifty-seven thousand, seven hundred seventeen".