266772161 has 4 divisors (see below), whose sum is σ = 271805652. Its totient is φ = 261738672.

The previous prime is 266772119. The next prime is 266772167. The reversal of 266772161 is 161277662.

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 202066225 + 64705936 = 14215^2 + 8044^2 .

It is a cyclic number.

It is not a de Polignac number, because 266772161 - 2⁶ = 266772097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266772167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2516666 + ... + 2516771.

It is an arithmetic number, because the mean of its divisors is an integer number (67951413).

Almost surely, 2^266772161 is an apocalyptic number.

It is an amenable number.

266772161 is a deficient number, since it is larger than the sum of its proper divisors (5033491).

266772161 is an equidigital number, since it uses as much as digits as its factorization.

266772161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5033490.

The product of its digits is 42336, while the sum is 38.

The square root of 266772161 is about 16333.1613902514. The cubic root of 266772161 is about 643.7444565960.

The spelling of 266772161 in words is "two hundred sixty-six million, seven hundred seventy-two thousand, one hundred sixty-one".