1666666659 has 16 divisors (see below), whose sum is σ = 2540293632. Its totient is φ = 952151808.

The previous prime is 1666666649. The next prime is 1666666667. The reversal of 1666666659 is 9566666661.

It is not a de Polignac number, because 1666666659 - 2⁸ = 1666666403 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1666666599 and 1666666608.

It is not an unprimeable number, because it can be changed into a prime (1666666649) 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, 121882 + ... + 134864.

It is an arithmetic number, because the mean of its divisors is an integer number (158768352).

Almost surely, 2^1666666659 is an apocalyptic number.

1666666659 is a deficient number, since it is larger than the sum of its proper divisors (873626973).

1666666659 is a wasteful number, since it uses less digits than its factorization.

1666666659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19106.

The product of its digits is 12597120, while the sum is 57.

The square root of 1666666659 is about 40824.8289524892. The cubic root of 1666666659 is about 1185.6310996787.

The spelling of 1666666659 in words is "one billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred fifty-nine".