39865 has 16 divisors (see below), whose sum is σ = 58752. Its totient is φ = 25344.

The previous prime is 39863. The next prime is 39869. The reversal of 39865 is 56893.

39865 is nontrivially palindromic in base 16.

39865 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

39865 is an esthetic number in base 4, because in such base its adjacent digits differ by 1.

It is a 3-Lehmer number, since φ(39865) divides (39865-1)³.

It is a cyclic number.

It is not a de Polignac number, because 39865 - 2¹ = 39863 is a prime.

39865 is strictly pandigital in base 6.

39865 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (39863) 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, 562 + ... + 628.

It is an arithmetic number, because the mean of its divisors is an integer number (3672).

It is a Poulet number, since it divides 2³⁹⁸⁶⁴-1.

2³⁹⁸⁶⁵ is an apocalyptic number.

39865 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

39865 is a deficient number, since it is larger than the sum of its proper divisors (18887).

39865 is a wasteful number, since it uses less digits than its factorization.

39865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96.

The product of its digits is 6480, while the sum is 31.

The square root of 39865 is about 199.6622147528. The cubic root of 39865 is about 34.1610011096.

The spelling of 39865 in words is "thirty-nine thousand, eight hundred sixty-five".