266257 has 4 divisors (see below), whose sum is σ = 267300. Its totient is φ = 265216.

The previous prime is 266239. The next prime is 266261. The reversal of 266257 is 752662.

It is a Cunningham number, because it is equal to 516²+1.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 163216 + 103041 = 404^2 + 321^2 .

It is a cyclic number.

It is not a de Polignac number, because 266257 - 2⁷ = 266129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266297) 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, 153 + ... + 745.

It is an arithmetic number, because the mean of its divisors is an integer number (66825).

2²⁶⁶²⁵⁷ is an apocalyptic number.

It is an amenable number.

266257 is a deficient number, since it is larger than the sum of its proper divisors (1043).

266257 is an equidigital number, since it uses as much as digits as its factorization.

266257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042.

The product of its digits is 5040, while the sum is 28.

The square root of 266257 is about 516.0009689913. Note that the first 3 decimals coincide. The cubic root of 266257 is about 64.3329813458.

The spelling of 266257 in words is "two hundred sixty-six thousand, two hundred fifty-seven".