66560555544 has 128 divisors (see below), whose sum is σ = 195835207680. Its totient is φ = 18455961600.

The previous prime is 66560555513. The next prime is 66560555587. The reversal of 66560555544 is 44555506566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1290312 + ... + 1340904.

It is an arithmetic number, because the mean of its divisors is an integer number (1529962560).

Almost surely, 2^66560555544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66560555544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97917603840).

66560555544 is an abundant number, since it is smaller than the sum of its proper divisors (129274652136).

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

66560555544 is a wasteful number, since it uses less digits than its factorization.

66560555544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50841 (or 50837 counting only the distinct ones).

The product of its (nonzero) digits is 10800000, while the sum is 51.

The spelling of 66560555544 in words is "sixty-six billion, five hundred sixty million, five hundred fifty-five thousand, five hundred forty-four".