1666506555506 has 32 divisors (see below), whose sum is σ = 2718977962176. Its totient is φ = 761464440000.

The previous prime is 1666506555491. The next prime is 1666506555523. The reversal of 1666506555506 is 6055556056661.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32040101 + ... + 32092071.

It is an arithmetic number, because the mean of its divisors is an integer number (84968061318).

Almost surely, 2^{1666506555506} is an apocalyptic number.

1666506555506 is a deficient number, since it is larger than the sum of its proper divisors (1052471406670).

1666506555506 is a wasteful number, since it uses less digits than its factorization.

1666506555506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64298.

The product of its (nonzero) digits is 24300000, while the sum is 56.

The spelling of 1666506555506 in words is "one trillion, six hundred sixty-six billion, five hundred six million, five hundred fifty-five thousand, five hundred six".