266505 has 16 divisors (see below), whose sum is σ = 432960. Its totient is φ = 139968.

The previous prime is 266491. The next prime is 266521. The reversal of 266505 is 505662.

It is not a de Polignac number, because 266505 - 2⁴ = 266489 is a prime.

It is a Curzon number.

266505 is a lucky number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1554 + ... + 1716.

It is an arithmetic number, because the mean of its divisors is an integer number (27060).

2²⁶⁶⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

266505 is a deficient number, since it is larger than the sum of its proper divisors (166455).

266505 is a wasteful number, since it uses less digits than its factorization.

266505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 266505 is about 516.2412226857. The cubic root of 266505 is about 64.3529490567.

The spelling of 266505 in words is "two hundred sixty-six thousand, five hundred five".