666766667 has 12 divisors (see below), whose sum is σ = 776955600. Its totient is φ = 570535056.

The previous prime is 666766663. The next prime is 666766669. The reversal of 666766667 is 766667666.

It is not a de Polignac number, because 666766667 - 2² = 666766663 is a prime.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666766663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17993 + ... + 40709.

It is an arithmetic number, because the mean of its divisors is an integer number (64746300).

Almost surely, 2^666766667 is an apocalyptic number.

666766667 is a deficient number, since it is larger than the sum of its proper divisors (110188933).

666766667 is a wasteful number, since it uses less digits than its factorization.

666766667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23330 (or 23323 counting only the distinct ones).

The product of its digits is 13716864, while the sum is 56.

The square root of 666766667 is about 25821.8254002307. The cubic root of 666766667 is about 873.6241417213.

Subtracting 666766667 from its reverse (766667666), we obtain a palindrome (99900999).

The spelling of 666766667 in words is "six hundred sixty-six million, seven hundred sixty-six thousand, six hundred sixty-seven".