166616380121 has 2 divisors, whose sum is σ = 166616380122. Its totient is φ = 166616380120.

The previous prime is 166616380069. The next prime is 166616380159. The reversal of 166616380121 is 121083616661.

166616380121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91107385600 + 75508994521 = 301840^2 + 274789^2 .

It is a cyclic number.

It is not a de Polignac number, because 166616380121 - 2⁶ = 166616380057 is a prime.

It is a super-2 number, since 2×166616380121² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166616380621) 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, 83308190060 + 83308190061.

It is an arithmetic number, because the mean of its divisors is an integer number (83308190061).

Almost surely, 2^166616380121 is an apocalyptic number.

It is an amenable number.

166616380121 is a deficient number, since it is larger than the sum of its proper divisors (1).

166616380121 is an equidigital number, since it uses as much as digits as its factorization.

166616380121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 41.

Adding to 166616380121 its reverse (121083616661), we get a palindrome (287699996782).

The spelling of 166616380121 in words is "one hundred sixty-six billion, six hundred sixteen million, three hundred eighty thousand, one hundred twenty-one".