1264686161 has 2 divisors, whose sum is σ = 1264686162. Its totient is φ = 1264686160.

The previous prime is 1264686149. The next prime is 1264686187. The reversal of 1264686161 is 1616864621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 877344400 + 387341761 = 29620^2 + 19681^2 .

It is an emirp because it is prime and its reverse (1616864621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1264686161 - 2¹⁸ = 1264424017 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 (1264686131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632343080 + 632343081.

It is an arithmetic number, because the mean of its divisors is an integer number (632343081).

Almost surely, 2^1264686161 is an apocalyptic number.

It is an amenable number.

1264686161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1264686161 is an equidigital number, since it uses as much as digits as its factorization.

1264686161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 41.

The square root of 1264686161 is about 35562.4262529991. The cubic root of 1264686161 is about 1081.4196468484.

The spelling of 1264686161 in words is "one billion, two hundred sixty-four million, six hundred eighty-six thousand, one hundred sixty-one".