399775 has 6 divisors (see below), whose sum is σ = 495752. Its totient is φ = 319800.

The previous prime is 399769. The next prime is 399781. The reversal of 399775 is 577993.

It is an interprime number because it is at equal distance from previous prime (399769) and next prime (399781).

It is not a de Polignac number, because 399775 - 2⁷ = 399647 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 7971 + ... + 8020.

2³⁹⁹⁷⁷⁵ is an apocalyptic number.

399775 is a deficient number, since it is larger than the sum of its proper divisors (95977).

399775 is a wasteful number, since it uses less digits than its factorization.

399775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16001 (or 15996 counting only the distinct ones).

The product of its digits is 59535, while the sum is 40.

The square root of 399775 is about 632.2776288941. The cubic root of 399775 is about 73.6668122635. Note that the first 3 decimals are identical.

The spelling of 399775 in words is "three hundred ninety-nine thousand, seven hundred seventy-five".