667646766 has 16 divisors (see below), whose sum is σ = 1483659600. Its totient is φ = 222548904.

The previous prime is 667646741. The next prime is 667646789.

667646766 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 12363829 = 667646766 / (6 + 6 + 7 + 6 + 4 + 6 + 7 + 6 + 6).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6181861 + ... + 6181968.

It is an arithmetic number, because the mean of its divisors is an integer number (92728725).

Almost surely, 2^667646766 is an apocalyptic number.

667646766 is an abundant number, since it is smaller than the sum of its proper divisors (816012834).

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

667646766 is a wasteful number, since it uses less digits than its factorization.

667646766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12363840 (or 12363834 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 54.

The square root of 667646766 is about 25838.8615461285. The cubic root of 667646766 is about 874.0083529338.

The spelling of 667646766 in words is "six hundred sixty-seven million, six hundred forty-six thousand, seven hundred sixty-six".