399799 has 4 divisors (see below), whose sum is σ = 401080. Its totient is φ = 398520.

The previous prime is 399793. The next prime is 399851. The reversal of 399799 is 997993.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 997993 = 23 ⋅43391.

It is a cyclic number.

It is not a de Polignac number, because 399799 - 2¹¹ = 397751 is a prime.

It is a Duffinian number.

399799 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172 + ... + 910.

It is an arithmetic number, because the mean of its divisors is an integer number (100270).

2³⁹⁹⁷⁹⁹ is an apocalyptic number.

399799 is a deficient number, since it is larger than the sum of its proper divisors (1281).

399799 is an equidigital number, since it uses as much as digits as its factorization.

399799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1280.

The product of its digits is 137781, while the sum is 46.

The square root of 399799 is about 632.2966076139. The cubic root of 399799 is about 73.6682863995.

It can be divided in two parts, 3997 and 99, that added together give a 12-th power (4096 = 2¹²).

The spelling of 399799 in words is "three hundred ninety-nine thousand, seven hundred ninety-nine".