266681891 has 12 divisors (see below), whose sum is σ = 321667632. Its totient is φ = 216551664.

The previous prime is 266681887. The next prime is 266681911. The reversal of 266681891 is 198186662.

It is not a de Polignac number, because 266681891 - 2² = 266681887 is a prime.

It is a super-2 number, since 2×266681891² = 142238461974671762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266681851) 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 11 ways as a sum of consecutive naturals, for example, 50240 + ... + 55293.

It is an arithmetic number, because the mean of its divisors is an integer number (26805636).

Almost surely, 2^266681891 is an apocalyptic number.

266681891 is a deficient number, since it is larger than the sum of its proper divisors (54985741).

266681891 is a wasteful number, since it uses less digits than its factorization.

266681891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105578 (or 105559 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The square root of 266681891 is about 16330.3977600057. The cubic root of 266681891 is about 643.6718386142.

The spelling of 266681891 in words is "two hundred sixty-six million, six hundred eighty-one thousand, eight hundred ninety-one".