166522210135685 has 4 divisors (see below), whose sum is σ = 199826652162828. Its totient is φ = 133217768108544.

The previous prime is 166522210135681. The next prime is 166522210135777. The reversal of 166522210135685 is 586531012225661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 123468232363876 + 43053977771809 = 11111626^2 + 6561553^2 .

It is a cyclic number.

It is not a de Polignac number, because 166522210135685 - 2² = 166522210135681 is a prime.

It is a super-2 number, since 2×166522210135685² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166522210135681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16652221013564 + ... + 16652221013573.

It is an arithmetic number, because the mean of its divisors is an integer number (49956663040707).

Almost surely, 2^{166522210135685} is an apocalyptic number.

It is an amenable number.

166522210135685 is a deficient number, since it is larger than the sum of its proper divisors (33304442027143).

166522210135685 is an equidigital number, since it uses as much as digits as its factorization.

166522210135685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33304442027142.

The product of its (nonzero) digits is 5184000, while the sum is 53.

The spelling of 166522210135685 in words is "one hundred sixty-six trillion, five hundred twenty-two billion, two hundred ten million, one hundred thirty-five thousand, six hundred eighty-five".