766666666666665 has 64 divisors (see below), whose sum is σ = 1363990121625600. Its totient is φ = 408580844559552.

The previous prime is 766666666666619. The next prime is 766666666666699. The reversal of 766666666666665 is 566666666666667.

It is not a de Polignac number, because 766666666666665 - 2⁸ = 766666666666409 is a prime.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1077721084 + ... + 1078432226.

It is an arithmetic number, because the mean of its divisors is an integer number (21312345650400).

Almost surely, 2^{766666666666665} is an apocalyptic number.

It is an amenable number.

766666666666665 is a deficient number, since it is larger than the sum of its proper divisors (597323454958935).

766666666666665 is a wasteful number, since it uses less digits than its factorization.

766666666666665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717163 (or 717157 counting only the distinct ones).

The product of its digits is 457124290560, while the sum is 90.

The spelling of 766666666666665 in words is "seven hundred sixty-six trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred sixty-five".