397135857 has 4 divisors (see below), whose sum is σ = 529514480. Its totient is φ = 264757236.

The previous prime is 397135813. The next prime is 397135883. The reversal of 397135857 is 758531793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 758531793 = 3 ⋅252843931.

It is not a de Polignac number, because 397135857 - 2¹¹ = 397133809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397135807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66189307 + ... + 66189312.

It is an arithmetic number, because the mean of its divisors is an integer number (132378620).

Almost surely, 2^397135857 is an apocalyptic number.

It is an amenable number.

397135857 is a deficient number, since it is larger than the sum of its proper divisors (132378623).

397135857 is a wasteful number, since it uses less digits than its factorization.

397135857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132378622.

The product of its digits is 793800, while the sum is 48.

The square root of 397135857 is about 19928.2677872413. The cubic root of 397135857 is about 735.0434867139.

The spelling of 397135857 in words is "three hundred ninety-seven million, one hundred thirty-five thousand, eight hundred fifty-seven".