1265640563266 has 8 divisors (see below), whose sum is σ = 2010135012300. Its totient is φ = 595595559168.

The previous prime is 1265640563191. The next prime is 1265640563273. The reversal of 1265640563266 is 6623650465621.

It can be written as a sum of positive squares in 2 ways, for example, as 1264659934041 + 980629225 = 1124571^2 + 31315^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 18612361191 + ... + 18612361258.

Almost surely, 2^{1265640563266} is an apocalyptic number.

1265640563266 is a deficient number, since it is larger than the sum of its proper divisors (744494449034).

1265640563266 is a wasteful number, since it uses less digits than its factorization.

1265640563266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37224722468.

The product of its (nonzero) digits is 9331200, while the sum is 52.

The spelling of 1265640563266 in words is "one trillion, two hundred sixty-five billion, six hundred forty million, five hundred sixty-three thousand, two hundred sixty-six".