166611117105506 has 4 divisors (see below), whose sum is σ = 249916675658262. Its totient is φ = 83305558552752.

The previous prime is 166611117105467. The next prime is 166611117105541. The reversal of 166611117105506 is 605501711116661.

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

It can be written as a sum of positive squares in only one way, i.e., 126925211999881 + 39685905105625 = 11266109^2 + 6299675^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41652779276375 + ... + 41652779276378.

Almost surely, 2^{166611117105506} is an apocalyptic number.

166611117105506 is a deficient number, since it is larger than the sum of its proper divisors (83305558552756).

166611117105506 is an equidigital number, since it uses as much as digits as its factorization.

166611117105506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83305558552755.

The product of its (nonzero) digits is 226800, while the sum is 47.

The spelling of 166611117105506 in words is "one hundred sixty-six trillion, six hundred eleven billion, one hundred seventeen million, one hundred five thousand, five hundred six".