1666556404011 has 24 divisors (see below), whose sum is σ = 2470694924880. Its totient is φ = 1081858502400.

The previous prime is 1666556403989. The next prime is 1666556404027. The reversal of 1666556404011 is 1104046556661.

It is not a de Polignac number, because 1666556404011 - 2⁵ = 1666556403979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666556404091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4142121 + ... + 4526618.

It is an arithmetic number, because the mean of its divisors is an integer number (102945621870).

Almost surely, 2^{1666556404011} is an apocalyptic number.

1666556404011 is a deficient number, since it is larger than the sum of its proper divisors (804138520869).

1666556404011 is a wasteful number, since it uses less digits than its factorization.

1666556404011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8669307 (or 8669304 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 1666556404011 in words is "one trillion, six hundred sixty-six billion, five hundred fifty-six million, four hundred four thousand, eleven".