66055665641 has 6 divisors (see below), whose sum is σ = 76840264170. Its totient is φ = 56619141936.

The previous prime is 66055665631. The next prime is 66055665667. The reversal of 66055665641 is 14656655066.

It can be written as a sum of positive squares in only one way, i.e., 65512962025 + 542703616 = 255955^2 + 23296^2 .

It is not a de Polignac number, because 66055665641 - 2¹⁰ = 66055664617 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 66055665641.

It is not an unprimeable number, because it can be changed into a prime (66055665631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 674037356 + ... + 674037453.

It is an arithmetic number, because the mean of its divisors is an integer number (12806710695).

Almost surely, 2^66055665641 is an apocalyptic number.

It is an amenable number.

66055665641 is a deficient number, since it is larger than the sum of its proper divisors (10784598529).

66055665641 is a wasteful number, since it uses less digits than its factorization.

66055665641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348074823 (or 1348074816 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 66055665641 in words is "sixty-six billion, fifty-five million, six hundred sixty-five thousand, six hundred forty-one".