399623 has 4 divisors (see below), whose sum is σ = 456720. Its totient is φ = 342528.

The previous prime is 399617. The next prime is 399643. The reversal of 399623 is 326993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399623 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 399623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399613) 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, 28538 + ... + 28551.

It is an arithmetic number, because the mean of its divisors is an integer number (114180).

2³⁹⁹⁶²³ is an apocalyptic number.

399623 is a deficient number, since it is larger than the sum of its proper divisors (57097).

399623 is an equidigital number, since it uses as much as digits as its factorization.

399623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57096.

The product of its digits is 8748, while the sum is 32.

The square root of 399623 is about 632.1574171043. The cubic root of 399623 is about 73.6574746988.

The spelling of 399623 in words is "three hundred ninety-nine thousand, six hundred twenty-three".