1666861084186 has 32 divisors (see below), whose sum is σ = 2549308704768. Its totient is φ = 817234427520.

The previous prime is 1666861084169. The next prime is 1666861084243. The reversal of 1666861084186 is 6814801686661.

It is a happy number.

It is a Smith number, since the sum of its digits (61) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24612591 + ... + 24680221.

It is an arithmetic number, because the mean of its divisors is an integer number (79665897024).

Almost surely, 2^{1666861084186} is an apocalyptic number.

1666861084186 is a deficient number, since it is larger than the sum of its proper divisors (882447620582).

1666861084186 is a wasteful number, since it uses less digits than its factorization.

1666861084186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68686.

The product of its (nonzero) digits is 15925248, while the sum is 61.

The spelling of 1666861084186 in words is "one trillion, six hundred sixty-six billion, eight hundred sixty-one million, eighty-four thousand, one hundred eighty-six".