393865 has 8 divisors (see below), whose sum is σ = 485640. Its totient is φ = 306432.

The previous prime is 393863. The next prime is 393871. The reversal of 393865 is 568393.

It can be written as a sum of positive squares in 4 ways, for example, as 65536 + 328329 = 256^2 + 573^2 .

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 393865 - 2¹ = 393863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 393865.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393863) 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, 880 + ... + 1249.

It is an arithmetic number, because the mean of its divisors is an integer number (60705).

2³⁹³⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

393865 is a deficient number, since it is larger than the sum of its proper divisors (91775).

393865 is a wasteful number, since it uses less digits than its factorization.

393865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2171.

The product of its digits is 19440, while the sum is 34.

The square root of 393865 is about 627.5866474042. The cubic root of 393865 is about 73.3019953336.

It can be divided in two parts, 3938 and 65, that multiplied together give a triangular number (255970 = T₇₁₅).

The spelling of 393865 in words is "three hundred ninety-three thousand, eight hundred sixty-five".