166611155993 has 2 divisors, whose sum is σ = 166611155994. Its totient is φ = 166611155992.

The previous prime is 166611155983. The next prime is 166611156037. The reversal of 166611155993 is 399551116661.

166611155993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129490583104 + 37120572889 = 359848^2 + 192667^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166611155993 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 (166611155983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83305577996 + 83305577997.

It is an arithmetic number, because the mean of its divisors is an integer number (83305577997).

Almost surely, 2^166611155993 is an apocalyptic number.

It is an amenable number.

166611155993 is a deficient number, since it is larger than the sum of its proper divisors (1).

166611155993 is an equidigital number, since it uses as much as digits as its factorization.

166611155993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1312200, while the sum is 53.

The spelling of 166611155993 in words is "one hundred sixty-six billion, six hundred eleven million, one hundred fifty-five thousand, nine hundred ninety-three".