397657 has 8 divisors (see below), whose sum is σ = 433160. Its totient is φ = 365040.

The previous prime is 397643. The next prime is 397673. The reversal of 397657 is 756793.

It can be written as a sum of positive squares in 4 ways, for example, as 254016 + 143641 = 504^2 + 379^2 .

It is a de Polignac number, because none of the positive numbers 2^k-397657 is a prime.

It is a d-powerful number, because it can be written as 3² + 9 + 6⁷ + 7² + 5 + 7⁶ .

It is a nialpdrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (397687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2107 + ... + 2287.

It is an arithmetic number, because the mean of its divisors is an integer number (54145).

2³⁹⁷⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

397657 is a deficient number, since it is larger than the sum of its proper divisors (35503).

397657 is an equidigital number, since it uses as much as digits as its factorization.

397657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 194 counting only the distinct ones).

The product of its digits is 39690, while the sum is 37.

The square root of 397657 is about 630.6005074530. The cubic root of 397657 is about 73.5364867357.

The spelling of 397657 in words is "three hundred ninety-seven thousand, six hundred fifty-seven".