1266406434661 has 4 divisors (see below), whose sum is σ = 1297294396524. Its totient is φ = 1235518472800.

The previous prime is 1266406434607. The next prime is 1266406434677. The reversal of 1266406434661 is 1664346046621.

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 113104416100 + 1153302018561 = 336310^2 + 1073919^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266406434661 - 2²⁵ = 1266372880229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266406134661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15443980870 + ... + 15443980951.

It is an arithmetic number, because the mean of its divisors is an integer number (324323599131).

Almost surely, 2^{1266406434661} is an apocalyptic number.

It is an amenable number.

1266406434661 is a deficient number, since it is larger than the sum of its proper divisors (30887961863).

1266406434661 is an equidigital number, since it uses as much as digits as its factorization.

1266406434661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30887961862.

The product of its (nonzero) digits is 2985984, while the sum is 49.

The spelling of 1266406434661 in words is "one trillion, two hundred sixty-six billion, four hundred six million, four hundred thirty-four thousand, six hundred sixty-one".