7865 has 12 divisors (see below), whose sum is σ = 11172. Its totient is φ = 5280.

The previous prime is 7853. The next prime is 7867. The reversal of 7865 is 5687.

7865 is nontrivially palindromic in base 8.

7865 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1936 + 5929 = 44^2 + 77^2 .

It is not a de Polignac number, because 7865 - 2¹⁰ = 6841 is a prime.

It is a Duffinian number.

Its product of digits (1680) is a multiple of the sum of its prime factors (40).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 599 + ... + 611.

It is an arithmetic number, because the mean of its divisors is an integer number (931).

2⁷⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

7865 is a deficient number, since it is larger than the sum of its proper divisors (3307).

7865 is a wasteful number, since it uses less digits than its factorization.

7865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40 (or 29 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 7865 is about 88.6848352313. The cubic root of 7865 is about 19.8868611873.

The spelling of 7865 in words is "seven thousand, eight hundred sixty-five".