166609971611243 has 2 divisors, whose sum is σ = 166609971611244. Its totient is φ = 166609971611242.

The previous prime is 166609971611203. The next prime is 166609971611351. The reversal of 166609971611243 is 342116179906661.

166609971611243 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 is an emirp because it is prime and its reverse (342116179906661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166609971611243 - 2⁶ = 166609971611179 is a prime.

It is not a weakly prime, because it can be changed into another prime (166609971611203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83304985805621 + 83304985805622.

It is an arithmetic number, because the mean of its divisors is an integer number (83304985805622).

Almost surely, 2^{166609971611243} is an apocalyptic number.

166609971611243 is a deficient number, since it is larger than the sum of its proper divisors (1).

166609971611243 is an equidigital number, since it uses as much as digits as its factorization.

166609971611243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17635968, while the sum is 62.

The spelling of 166609971611243 in words is "one hundred sixty-six trillion, six hundred nine billion, nine hundred seventy-one million, six hundred eleven thousand, two hundred forty-three".