666818960 has 20 divisors (see below), whose sum is σ = 1550354268. Its totient is φ = 266727552.

The previous prime is 666818941. The next prime is 666818963. The reversal of 666818960 is 69818666.

It can be written as a sum of positive squares in 2 ways, for example, as 518563984 + 148254976 = 22772^2 + 12176^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 666818899 and 666818908.

It is not an unprimeable number, because it can be changed into a prime (666818963) 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 3 ways as a sum of consecutive naturals, for example, 4167539 + ... + 4167698.

Almost surely, 2^666818960 is an apocalyptic number.

It is an amenable number.

666818960 is an abundant number, since it is smaller than the sum of its proper divisors (883535308).

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

666818960 is a wasteful number, since it uses less digits than its factorization.

666818960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8335250 (or 8335244 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 50.

The square root of 666818960 is about 25822.8379540282. The cubic root of 666818960 is about 873.6469799121.

The spelling of 666818960 in words is "six hundred sixty-six million, eight hundred eighteen thousand, nine hundred sixty".