666309903666 has 32 divisors (see below), whose sum is σ = 1461798950976. Its totient is φ = 200796552000.

The previous prime is 666309903641. The next prime is 666309903683.

666309903666 is nontrivially palindromic in base 10.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 27876465 + ... + 27900356.

It is an arithmetic number, because the mean of its divisors is an integer number (45681217218).

Almost surely, 2^666309903666 is an apocalyptic number.

666309903666 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

666309903666 is an abundant number, since it is smaller than the sum of its proper divisors (795489047310).

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

666309903666 is a wasteful number, since it uses less digits than its factorization.

666309903666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55777018.

The product of its (nonzero) digits is 34012224, while the sum is 60.

The spelling of 666309903666 in words is "six hundred sixty-six billion, three hundred nine million, nine hundred three thousand, six hundred sixty-six".