6511386666 has 32 divisors (see below), whose sum is σ = 13145407488. Its totient is φ = 2150103600.

The previous prime is 6511386619. The next prime is 6511386691. The reversal of 6511386666 is 6666831156.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 322711 + ... + 342293.

It is an arithmetic number, because the mean of its divisors is an integer number (410793984).

Almost surely, 2^6511386666 is an apocalyptic number.

6511386666 is an abundant number, since it is smaller than the sum of its proper divisors (6634020822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6511386666 is a wasteful number, since it uses less digits than its factorization.

6511386666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20106.

The product of its digits is 933120, while the sum is 48.

The square root of 6511386666 is about 80693.1636881341. The cubic root of 6511386666 is about 1867.3447082654.

The spelling of 6511386666 in words is "six billion, five hundred eleven million, three hundred eighty-six thousand, six hundred sixty-six".