399257 has 4 divisors (see below), whose sum is σ = 416640. Its totient is φ = 381876.

The previous prime is 399241. The next prime is 399263. The reversal of 399257 is 752993.

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.

It is a cyclic number.

It is not a de Polignac number, because 399257 - 2⁴ = 399241 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399227) 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, 8657 + ... + 8702.

It is an arithmetic number, because the mean of its divisors is an integer number (104160).

2³⁹⁹²⁵⁷ is an apocalyptic number.

It is an amenable number.

399257 is a deficient number, since it is larger than the sum of its proper divisors (17383).

399257 is a wasteful number, since it uses less digits than its factorization.

399257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17382.

The product of its digits is 17010, while the sum is 35.

The square root of 399257 is about 631.8678659340. The cubic root of 399257 is about 73.6349811068.

It can be divided in two parts, 399 and 257, that added together give a palindrome (656).

The spelling of 399257 in words is "three hundred ninety-nine thousand, two hundred fifty-seven".