166105556117 has 2 divisors, whose sum is σ = 166105556118. Its totient is φ = 166105556116.

The previous prime is 166105556093. The next prime is 166105556203. The reversal of 166105556117 is 711655501661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91183465156 + 74922090961 = 301966^2 + 273719^2 .

It is a cyclic number.

It is not a de Polignac number, because 166105556117 - 2¹⁶ = 166105490581 is a prime.

It is a super-2 number, since 2×166105556117² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166105556317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83052778058 + 83052778059.

It is an arithmetic number, because the mean of its divisors is an integer number (83052778059).

Almost surely, 2^166105556117 is an apocalyptic number.

It is an amenable number.

166105556117 is a deficient number, since it is larger than the sum of its proper divisors (1).

166105556117 is an equidigital number, since it uses as much as digits as its factorization.

166105556117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 189000, while the sum is 44.

The spelling of 166105556117 in words is "one hundred sixty-six billion, one hundred five million, five hundred fifty-six thousand, one hundred seventeen".