399779 has 8 divisors (see below), whose sum is σ = 429840. Its totient is φ = 370656.

The previous prime is 399769. The next prime is 399781. The reversal of 399779 is 977993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 399779 - 2⁸ = 399523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399719) 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, 809 + ... + 1205.

It is an arithmetic number, because the mean of its divisors is an integer number (53730).

2³⁹⁹⁷⁷⁹ is an apocalyptic number.

399779 is a deficient number, since it is larger than the sum of its proper divisors (30061).

399779 is a wasteful number, since it uses less digits than its factorization.

399779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469.

The product of its digits is 107163, while the sum is 44.

The square root of 399779 is about 632.2807920537. The cubic root of 399779 is about 73.6670579570.

The spelling of 399779 in words is "three hundred ninety-nine thousand, seven hundred seventy-nine".