166551366316205 has 32 divisors (see below), whose sum is σ = 215409234436704. Its totient is φ = 122892584103936.

The previous prime is 166551366316201. The next prime is 166551366316211. The reversal of 166551366316205 is 502613663155661.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 7809459400681 + 158741906915524 = 2794541^2 + 12599282^2 .

It is a cyclic number.

It is not a de Polignac number, because 166551366316205 - 2² = 166551366316201 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166551366316201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 901271777 + ... + 901456553.

It is an arithmetic number, because the mean of its divisors is an integer number (6731538576147).

Almost surely, 2^{166551366316205} is an apocalyptic number.

It is an amenable number.

166551366316205 is a deficient number, since it is larger than the sum of its proper divisors (48857868120499).

166551366316205 is a wasteful number, since it uses less digits than its factorization.

166551366316205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195905.

The product of its (nonzero) digits is 17496000, while the sum is 56.

The spelling of 166551366316205 in words is "one hundred sixty-six trillion, five hundred fifty-one billion, three hundred sixty-six million, three hundred sixteen thousand, two hundred five".