399217 has 16 divisors (see below), whose sum is σ = 508032. Its totient is φ = 305280.

The previous prime is 399197. The next prime is 399221. The reversal of 399217 is 712993.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399217 is a prime.

399217 is a lucky 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 15 ways as a sum of consecutive naturals, for example, 3678 + ... + 3784.

It is an arithmetic number, because the mean of its divisors is an integer number (31752).

2³⁹⁹²¹⁷ is an apocalyptic number.

It is an amenable number.

399217 is a deficient number, since it is larger than the sum of its proper divisors (108815).

399217 is a wasteful number, since it uses less digits than its factorization.

399217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168.

The product of its digits is 3402, while the sum is 31.

The square root of 399217 is about 631.8362129540. The cubic root of 399217 is about 73.6325219576.

It can be divided in two parts, 399 and 217, that added together give a palindrome (616).

The spelling of 399217 in words is "three hundred ninety-nine thousand, two hundred seventeen".