266640961 has 2 divisors, whose sum is σ = 266640962. Its totient is φ = 266640960.

The previous prime is 266640949. The next prime is 266640973. The reversal of 266640961 is 169046662.

It is a balanced prime because it is at equal distance from previous prime (266640949) and next prime (266640973).

It can be written as a sum of positive squares in only one way, i.e., 252810000 + 13830961 = 15900^2 + 3719^2 .

It is a cyclic number.

It is not a de Polignac number, because 266640961 - 2⁵ = 266640929 is a prime.

It is not a weakly prime, because it can be changed into another prime (266640931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 133320480 + 133320481.

It is an arithmetic number, because the mean of its divisors is an integer number (133320481).

Almost surely, 2^266640961 is an apocalyptic number.

It is an amenable number.

266640961 is a deficient number, since it is larger than the sum of its proper divisors (1).

266640961 is an equidigital number, since it uses as much as digits as its factorization.

266640961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 266640961 is about 16329.1445275005. The cubic root of 266640961 is about 643.6389069489.

The spelling of 266640961 in words is "two hundred sixty-six million, six hundred forty thousand, nine hundred sixty-one".