666141661 has 4 divisors (see below), whose sum is σ = 672367392. Its totient is φ = 659915932.

The previous prime is 666141643. The next prime is 666141727. The reversal of 666141661 is 166141666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166141666 = 2 ⋅83070833.

It is a cyclic number.

It is not a de Polignac number, because 666141661 - 2⁹ = 666141149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666141661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666141611) 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, 3112705 + ... + 3112918.

It is an arithmetic number, because the mean of its divisors is an integer number (168091848).

Almost surely, 2^666141661 is an apocalyptic number.

It is an amenable number.

666141661 is a deficient number, since it is larger than the sum of its proper divisors (6225731).

666141661 is a wasteful number, since it uses less digits than its factorization.

666141661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6225730.

The product of its digits is 31104, while the sum is 37.

The square root of 666141661 is about 25809.7202813204. The cubic root of 666141661 is about 873.3510871664.

The spelling of 666141661 in words is "six hundred sixty-six million, one hundred forty-one thousand, six hundred sixty-one".