666787667 has 8 divisors (see below), whose sum is σ = 820661856. Its totient is φ = 527568192.

The previous prime is 666787661. The next prime is 666787669. The reversal of 666787667 is 766787666.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 666787667 - 2¹⁰ = 666786643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666787661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3663578 + ... + 3663759.

It is an arithmetic number, because the mean of its divisors is an integer number (102582732).

Almost surely, 2^666787667 is an apocalyptic number.

666787667 is a deficient number, since it is larger than the sum of its proper divisors (153874189).

666787667 is a wasteful number, since it uses less digits than its factorization.

666787667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7327357.

The product of its digits is 21337344, while the sum is 59.

The square root of 666787667 is about 25822.2320297839. The cubic root of 666787667 is about 873.6333133028.

Subtracting 666787667 from its reverse (766787666), we obtain a palindrome (99999999).

The spelling of 666787667 in words is "six hundred sixty-six million, seven hundred eighty-seven thousand, six hundred sixty-seven".