399965 has 8 divisors (see below), whose sum is σ = 483840. Its totient is φ = 317392.

The previous prime is 399953. The next prime is 399979. The reversal of 399965 is 569993.

It is a happy number.

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 399965 - 2¹⁰ = 398941 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 596 + ... + 1074.

It is an arithmetic number, because the mean of its divisors is an integer number (60480).

2³⁹⁹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

399965 is a deficient number, since it is larger than the sum of its proper divisors (83875).

399965 is a wasteful number, since it uses less digits than its factorization.

399965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651.

The product of its digits is 65610, while the sum is 41.

The square root of 399965 is about 632.4278614988. The cubic root of 399965 is about 73.6784808918.

The spelling of 399965 in words is "three hundred ninety-nine thousand, nine hundred sixty-five".