266591 has 4 divisors (see below), whose sum is σ = 287112. Its totient is φ = 246072.

The previous prime is 266587. The next prime is 266599. The reversal of 266591 is 195662.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 266591 - 2² = 266587 is a prime.

It is a super-2 number, since 2×266591² = 142141522562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266599) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10241 + ... + 10266.

It is an arithmetic number, because the mean of its divisors is an integer number (71778).

2²⁶⁶⁵⁹¹ is an apocalyptic number.

266591 is a deficient number, since it is larger than the sum of its proper divisors (20521).

266591 is a wasteful number, since it uses less digits than its factorization.

266591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20520.

The product of its digits is 3240, while the sum is 29.

The square root of 266591 is about 516.3245103615. The cubic root of 266591 is about 64.3598704508.

The spelling of 266591 in words is "two hundred sixty-six thousand, five hundred ninety-one".