1266105257 has 4 divisors (see below), whose sum is σ = 1300324356. Its totient is φ = 1231886160.

The previous prime is 1266105251. The next prime is 1266105319. The reversal of 1266105257 is 7525016621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 958769296 + 307335961 = 30964^2 + 17531^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266105257 - 2¹⁰ = 1266104233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1266105251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17109494 + ... + 17109567.

It is an arithmetic number, because the mean of its divisors is an integer number (325081089).

Almost surely, 2^1266105257 is an apocalyptic number.

It is an amenable number.

1266105257 is a deficient number, since it is larger than the sum of its proper divisors (34219099).

1266105257 is an equidigital number, since it uses as much as digits as its factorization.

1266105257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34219098.

The product of its (nonzero) digits is 25200, while the sum is 35.

The square root of 1266105257 is about 35582.3728410571. The cubic root of 1266105257 is about 1081.8239802706.

The spelling of 1266105257 in words is "one billion, two hundred sixty-six million, one hundred five thousand, two hundred fifty-seven".