166666685123 has 2 divisors, whose sum is σ = 166666685124. Its totient is φ = 166666685122.

The previous prime is 166666685093. The next prime is 166666685137. The reversal of 166666685123 is 321586666661.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166666685123 - 2¹⁰ = 166666684099 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (166666684123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83333342561 + 83333342562.

It is an arithmetic number, because the mean of its divisors is an integer number (83333342562).

Almost surely, 2^166666685123 is an apocalyptic number.

166666685123 is a deficient number, since it is larger than the sum of its proper divisors (1).

166666685123 is an equidigital number, since it uses as much as digits as its factorization.

166666685123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11197440, while the sum is 56.

The spelling of 166666685123 in words is "one hundred sixty-six billion, six hundred sixty-six million, six hundred eighty-five thousand, one hundred twenty-three".