266805 has 54 divisors (see below), whose sum is σ = 591318. Its totient is φ = 110880.

The previous prime is 266801. The next prime is 266821. The reversal of 266805 is 508662.

It can be written as a sum of positive squares in only one way, i.e., 213444 + 53361 = 462^2 + 231^2 .

It is not a de Polignac number, because 266805 - 2² = 266801 is a prime.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266801) by changing a digit.

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 53 ways as a sum of consecutive naturals, for example, 24250 + ... + 24260.

2²⁶⁶⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

266805 is an abundant number, since it is smaller than the sum of its proper divisors (324513).

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

266805 is a wasteful number, since it uses less digits than its factorization.

266805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47 (or 26 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 266805 is about 516.5317028025. The cubic root of 266805 is about 64.3770869968.

Multiplying 266805 by its product of nonzero digits (2880), we get a square (768398400 = 27720²).

The spelling of 266805 in words is "two hundred sixty-six thousand, eight hundred five".