6661866141 has 36 divisors (see below), whose sum is σ = 11410441952. Its totient is φ = 3804857064.

The previous prime is 6661866077. The next prime is 6661866149. The reversal of 6661866141 is 1416681666.

It is a happy number.

It is not a de Polignac number, because 6661866141 - 2⁶ = 6661866077 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661866149) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 3365290 + ... + 3367268.

Almost surely, 2^6661866141 is an apocalyptic number.

It is an amenable number.

6661866141 is a deficient number, since it is larger than the sum of its proper divisors (4748575811).

6661866141 is an frugal number, since it uses more digits than its factorization.

6661866141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3980 (or 1989 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 6661866141 is about 81620.2557028585. The cubic root of 6661866141 is about 1881.6202025266.

The spelling of 6661866141 in words is "six billion, six hundred sixty-one million, eight hundred sixty-six thousand, one hundred forty-one".