665892 has 36 divisors (see below), whose sum is σ = 1719900. Its totient is φ = 217152.

The previous prime is 665857. The next prime is 665897. The reversal of 665892 is 298566.

It can be written as a sum of positive squares in 2 ways, for example, as 484416 + 181476 = 696^2 + 426^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a d-powerful number, because it can be written as 6 + 6⁶ + 8⁵ + 5⁵ + 9⁵ + 2¹⁹ .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665892.

It is not an unprimeable number, because it can be changed into a prime (665897) by changing a digit.

665892 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1734 + ... + 2082.

It is an arithmetic number, because the mean of its divisors is an integer number (47775).

2⁶⁶⁵⁸⁹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665892, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (859950).

665892 is an abundant number, since it is smaller than the sum of its proper divisors (1054008).

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

665892 is a wasteful number, since it uses less digits than its factorization.

665892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412 (or 407 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 665892 is about 816.0220585254. The cubic root of 665892 is about 87.3241966758.

Subtracting from 665892 its sum of digits (36), we obtain a square (665856 = 816²).

The spelling of 665892 in words is "six hundred sixty-five thousand, eight hundred ninety-two".