6661630361666 has 20 divisors (see below), whose sum is σ = 11657159510502. Its totient is φ = 2854984438656.

The previous prime is 6661630361651. The next prime is 6661630361741.

6661630361666 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 4902083824225 + 1759546537441 = 2214065^2 + 1326479^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 693626015 + ... + 693635618.

Almost surely, 2^{6661630361666} is an apocalyptic number.

6661630361666 is a deficient number, since it is larger than the sum of its proper divisors (4995529148836).

6661630361666 is an equidigital number, since it uses as much as digits as its factorization.

6661630361666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1387261663 (or 1387261642 counting only the distinct ones).

The product of its (nonzero) digits is 15116544, while the sum is 56.

The spelling of 6661630361666 in words is "six trillion, six hundred sixty-one billion, six hundred thirty million, three hundred sixty-one thousand, six hundred sixty-six".