399765 has 16 divisors (see below), whose sum is σ = 662400. Its totient is φ = 205632.

The previous prime is 399761. The next prime is 399769. The reversal of 399765 is 567993.

It is an interprime number because it is at equal distance from previous prime (399761) and next prime (399769).

It is not a de Polignac number, because 399765 - 2² = 399761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399761) 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, 25 + ... + 894.

It is an arithmetic number, because the mean of its divisors is an integer number (41400).

2³⁹⁹⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

399765 is a deficient number, since it is larger than the sum of its proper divisors (262635).

399765 is a wasteful number, since it uses less digits than its factorization.

399765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 956.

The product of its digits is 51030, while the sum is 39.

The square root of 399765 is about 632.2697209261. The cubic root of 399765 is about 73.6661980228. Note that the first 3 decimals are identical.

The spelling of 399765 in words is "three hundred ninety-nine thousand, seven hundred sixty-five".