1266416805161 has 2 divisors, whose sum is σ = 1266416805162. Its totient is φ = 1266416805160.

The previous prime is 1266416805131. The next prime is 1266416805191. The reversal of 1266416805161 is 1615086146621.

It is a balanced prime because it is at equal distance from previous prime (1266416805131) and next prime (1266416805191).

It can be written as a sum of positive squares in only one way, i.e., 910461380761 + 355955424400 = 954181^2 + 596620^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266416805161 - 2¹⁸ = 1266416543017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1266416805131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633208402580 + 633208402581.

It is an arithmetic number, because the mean of its divisors is an integer number (633208402581).

Almost surely, 2^{1266416805161} is an apocalyptic number.

It is an amenable number.

1266416805161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266416805161 is an equidigital number, since it uses as much as digits as its factorization.

1266416805161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 47.

The spelling of 1266416805161 in words is "one trillion, two hundred sixty-six billion, four hundred sixteen million, eight hundred five thousand, one hundred sixty-one".