666667767766666 has 8 divisors (see below), whose sum is σ = 1058825278217700. Its totient is φ = 313726008360768.

The previous prime is 666667767766657. The next prime is 666667767766691.

666667767766666 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 650192116288225 + 16475651478441 = 25498865^2 + 4059021^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9803937761241 + ... + 9803937761308.

Almost surely, 2^{666667767766666} is an apocalyptic number.

666667767766666 is a deficient number, since it is larger than the sum of its proper divisors (392157510451034).

666667767766666 is a wasteful number, since it uses less digits than its factorization.

666667767766666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19607875522568.

The product of its digits is 871075731456, while the sum is 94.

The spelling of 666667767766666 in words is "six hundred sixty-six trillion, six hundred sixty-seven billion, seven hundred sixty-seven million, seven hundred sixty-six thousand, six hundred sixty-six".