166610005165661 has 2 divisors, whose sum is σ = 166610005165662. Its totient is φ = 166610005165660.

The previous prime is 166610005165627. The next prime is 166610005165693. The reversal of 166610005165661 is 166561500016661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83993449062436 + 82616556103225 = 9164794^2 + 9089365^2 .

It is a cyclic number.

It is not a de Polignac number, because 166610005165661 - 2³⁴ = 166592825296477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166610005665661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83305002582830 + 83305002582831.

It is an arithmetic number, because the mean of its divisors is an integer number (83305002582831).

Almost surely, 2^{166610005165661} is an apocalyptic number.

It is an amenable number.

166610005165661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166610005165661 is an equidigital number, since it uses as much as digits as its factorization.

166610005165661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1166400, while the sum is 50.

The spelling of 166610005165661 in words is "one hundred sixty-six trillion, six hundred ten billion, five million, one hundred sixty-five thousand, six hundred sixty-one".