166685016653 has 2 divisors, whose sum is σ = 166685016654. Its totient is φ = 166685016652.

The previous prime is 166685016649. The next prime is 166685016703. The reversal of 166685016653 is 356610586661.

166685016653 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 can be written as a sum of positive squares in only one way, i.e., 143128292329 + 23556724324 = 378323^2 + 153482^2 .

It is a cyclic number.

It is not a de Polignac number, because 166685016653 - 2² = 166685016649 is a prime.

It is a super-2 number, since 2×166685016653² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 166685016595 and 166685016604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166685016353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83342508326 + 83342508327.

It is an arithmetic number, because the mean of its divisors is an integer number (83342508327).

Almost surely, 2^166685016653 is an apocalyptic number.

It is an amenable number.

166685016653 is a deficient number, since it is larger than the sum of its proper divisors (1).

166685016653 is an equidigital number, since it uses as much as digits as its factorization.

166685016653 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4665600, while the sum is 53.

The spelling of 166685016653 in words is "one hundred sixty-six billion, six hundred eighty-five million, sixteen thousand, six hundred fifty-three".