1186645661 has 2 divisors, whose sum is σ = 1186645662. Its totient is φ = 1186645660.

The previous prime is 1186645651. The next prime is 1186645687. The reversal of 1186645661 is 1665466811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 880605625 + 306040036 = 29675^2 + 17494^2 .

It is an emirp because it is prime and its reverse (1665466811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1186645661 - 2⁶ = 1186645597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1186645651) by changing a digit.

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 as a sum of consecutive naturals, namely, 593322830 + 593322831.

It is an arithmetic number, because the mean of its divisors is an integer number (593322831).

Almost surely, 2^1186645661 is an apocalyptic number.

It is an amenable number.

1186645661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1186645661 is an equidigital number, since it uses as much as digits as its factorization.

1186645661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 44.

The square root of 1186645661 is about 34447.7235967778. The cubic root of 1186645661 is about 1058.7018822055.

The spelling of 1186645661 in words is "one billion, one hundred eighty-six million, six hundred forty-five thousand, six hundred sixty-one".