666447744666 has 16 divisors (see below), whose sum is σ = 1454067806688. Its totient is φ = 201953862000.

The previous prime is 666447744647. The next prime is 666447744671.

666447744666 is nontrivially palindromic in base 10.

666447744666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66), and also a Moran number because the ratio is a prime number: 10097693101 = 666447744666 / (6 + 6 + 6 + 4 + 4 + 7 + 7 + 4 + 4 + 6 + 6 + 6).

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 666447744597 and 666447744606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5048846485 + ... + 5048846616.

It is an arithmetic number, because the mean of its divisors is an integer number (90879237918).

Almost surely, 2^666447744666 is an apocalyptic number.

666447744666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666447744666 is an abundant number, since it is smaller than the sum of its proper divisors (787620062022).

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

666447744666 is a wasteful number, since it uses less digits than its factorization.

666447744666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10097693117.

The product of its digits is 585252864, while the sum is 66.

The spelling of 666447744666 in words is "six hundred sixty-six billion, four hundred forty-seven million, seven hundred forty-four thousand, six hundred sixty-six".