266544244252261 has 4 divisors (see below), whose sum is σ = 266544284402124. Its totient is φ = 266544204102400.

The previous prime is 266544244252183. The next prime is 266544244252361. The reversal of 266544244252261 is 162252442445662.

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

It can be written as a sum of positive squares in 2 ways, for example, as 32021666595361 + 234522577656900 = 5658769^2 + 15314130^2 .

It is a cyclic number.

It is not a de Polignac number, because 266544244252261 - 2²⁵ = 266544210697829 is a prime.

It is a super-2 number, since 2×266544244252261² (a number of 30 digits) 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 (266544244252361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7484860 + ... + 24271621.

It is an arithmetic number, because the mean of its divisors is an integer number (66636071100531).

Almost surely, 2^{266544244252261} is an apocalyptic number.

It is an amenable number.

266544244252261 is a deficient number, since it is larger than the sum of its proper divisors (40149863).

266544244252261 is an equidigital number, since it uses as much as digits as its factorization.

266544244252261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40149862.

The product of its digits is 44236800, while the sum is 55.

The spelling of 266544244252261 in words is "two hundred sixty-six trillion, five hundred forty-four billion, two hundred forty-four million, two hundred fifty-two thousand, two hundred sixty-one".