266778133 has 2 divisors, whose sum is σ = 266778134. Its totient is φ = 266778132.

The previous prime is 266778131. The next prime is 266778139. The reversal of 266778133 is 331877662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138250564 + 128527569 = 11758^2 + 11337^2 .

It is a cyclic number.

It is not a de Polignac number, because 266778133 - 2¹ = 266778131 is a prime.

Together with 266778131, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 266778133.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (266778131) 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 as a sum of consecutive naturals, namely, 133389066 + 133389067.

It is an arithmetic number, because the mean of its divisors is an integer number (133389067).

Almost surely, 2^266778133 is an apocalyptic number.

It is an amenable number.

266778133 is a deficient number, since it is larger than the sum of its proper divisors (1).

266778133 is an equidigital number, since it uses as much as digits as its factorization.

266778133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 43.

The square root of 266778133 is about 16333.3442074794. The cubic root of 266778133 is about 643.7492602122.

The spelling of 266778133 in words is "two hundred sixty-six million, seven hundred seventy-eight thousand, one hundred thirty-three".