1666666666664 has 64 divisors (see below), whose sum is σ = 3223973748240. Its totient is φ = 807241738240.

The previous prime is 1666666666661. The next prime is 1666666666669. The reversal of 1666666666664 is 4666666666661.

It can be written as a sum of positive squares in 8 ways, for example, as 813153062500 + 853513604164 = 901750^2 + 923858^2 .

It is not an unprimeable number, because it can be changed into a prime (1666666666661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43844114 + ... + 43882110.

Almost surely, 2^{1666666666664} is an apocalyptic number.

It is an amenable number.

1666666666664 is a deficient number, since it is larger than the sum of its proper divisors (1557307081576).

1666666666664 is a wasteful number, since it uses less digits than its factorization.

1666666666664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38990 (or 38986 counting only the distinct ones).

The product of its digits is 1451188224, while the sum is 71.

The spelling of 1666666666664 in words is "one trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred sixty-four".