1666105505555 has 8 divisors (see below), whose sum is σ = 2037049750512. Its totient is φ = 1307735641888.

The previous prime is 1666105505543. The next prime is 1666105505557. The reversal of 1666105505555 is 5555055016661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1666105505555 - 2¹⁴ = 1666105489171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666105505557) 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, 3143595029 + ... + 3143595558.

It is an arithmetic number, because the mean of its divisors is an integer number (254631218814).

Almost surely, 2^{1666105505555} is an apocalyptic number.

1666105505555 is a deficient number, since it is larger than the sum of its proper divisors (370944244957).

1666105505555 is an equidigital number, since it uses as much as digits as its factorization.

1666105505555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6287190645.

The product of its (nonzero) digits is 3375000, while the sum is 50.

The spelling of 1666105505555 in words is "one trillion, six hundred sixty-six billion, one hundred five million, five hundred five thousand, five hundred fifty-five".