1666115117 has 2 divisors, whose sum is σ = 1666115118. Its totient is φ = 1666115116.

The previous prime is 1666115029. The next prime is 1666115123. The reversal of 1666115117 is 7115116661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 920879716 + 745235401 = 30346^2 + 27299^2 .

It is an emirp because it is prime and its reverse (7115116661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1666115117 - 2²⁴ = 1649337901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666115137) 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, 833057558 + 833057559.

It is an arithmetic number, because the mean of its divisors is an integer number (833057559).

Almost surely, 2^1666115117 is an apocalyptic number.

It is an amenable number.

1666115117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666115117 is an equidigital number, since it uses as much as digits as its factorization.

1666115117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 35.

The square root of 1666115117 is about 40818.0734111741. The cubic root of 1666115117 is about 1185.5003001792.

The spelling of 1666115117 in words is "one billion, six hundred sixty-six million, one hundred fifteen thousand, one hundred seventeen".