266097561 has 4 divisors (see below), whose sum is σ = 354796752. Its totient is φ = 177398372.

The previous prime is 266097547. The next prime is 266097589. The reversal of 266097561 is 165790662.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 266097561 - 2⁹ = 266097049 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (266097541) 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, 44349591 + ... + 44349596.

It is an arithmetic number, because the mean of its divisors is an integer number (88699188).

Almost surely, 2^266097561 is an apocalyptic number.

It is an amenable number.

266097561 is a deficient number, since it is larger than the sum of its proper divisors (88699191).

266097561 is an equidigital number, since it uses as much as digits as its factorization.

266097561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88699190.

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 266097561 is about 16312.4970804595. The cubic root of 266097561 is about 643.2013757172.

The spelling of 266097561 in words is "two hundred sixty-six million, ninety-seven thousand, five hundred sixty-one".