765666 has 32 divisors (see below), whose sum is σ = 1857600. Its totient is φ = 231840.

The previous prime is 765659. The next prime is 765673. The reversal of 765666 is 666567.

It is an interprime number because it is at equal distance from previous prime (765659) and next prime (765673).

It is an Ulam number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 765666.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 765666.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (58050).

2⁷⁶⁵⁶⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 765666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928800).

765666 is an abundant number, since it is smaller than the sum of its proper divisors (1091934).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

765666 is a wasteful number, since it uses less digits than its factorization.

765666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311 (or 1305 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 765666 is about 875.0234282578. The cubic root of 765666 is about 91.4842757177.

Subtracting from 765666 its reverse (666567), we obtain a palindrome (99099).

It can be divided in two parts, 765 and 666, that added together give a triangular number (1431 = T₅₃).

The spelling of 765666 in words is "seven hundred sixty-five thousand, six hundred sixty-six".