266461561 has 4 divisors (see below), whose sum is σ = 267724624. Its totient is φ = 265198500.

The previous prime is 266461511. The next prime is 266461577. The reversal of 266461561 is 165164662.

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 266461561 - 2¹⁵ = 266428793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 266461561.

It is not an unprimeable number, because it can be changed into a prime (266461511) 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, 631215 + ... + 631636.

It is an arithmetic number, because the mean of its divisors is an integer number (66931156).

Almost surely, 2^266461561 is an apocalyptic number.

It is an amenable number.

266461561 is a deficient number, since it is larger than the sum of its proper divisors (1263063).

266461561 is a wasteful number, since it uses less digits than its factorization.

266461561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1263062.

The product of its digits is 51840, while the sum is 37.

The square root of 266461561 is about 16323.6503576865. The cubic root of 266461561 is about 643.4945246235.

The spelling of 266461561 in words is "two hundred sixty-six million, four hundred sixty-one thousand, five hundred sixty-one".