181863658666 has 16 divisors (see below), whose sum is σ = 280467451656. Its totient is φ = 88379755776.

The previous prime is 181863658661. The next prime is 181863658783. The reversal of 181863658666 is 666856368181.

181863658666 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 127074425625 + 54789233041 = 356475^2 + 234071^2 .

It is a junction number, because it is equal to n+sod(n) for n = 181863658598 and 181863658607.

It is not an unprimeable number, because it can be changed into a prime (181863658661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1242091 + ... + 1380766.

Almost surely, 2^181863658666 is an apocalyptic number.

181863658666 is a deficient number, since it is larger than the sum of its proper divisors (98603792990).

181863658666 is a wasteful number, since it uses less digits than its factorization.

181863658666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2623833.

The product of its digits is 59719680, while the sum is 64.

The spelling of 181863658666 in words is "one hundred eighty-one billion, eight hundred sixty-three million, six hundred fifty-eight thousand, six hundred sixty-six".