66005555056 has 60 divisors (see below), whose sum is σ = 149250192168. Its totient is φ = 28195848576.

The previous prime is 66005555041. The next prime is 66005555081. The reversal of 66005555056 is 65055550066.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 103570 + ... + 377806.

Almost surely, 2^66005555056 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 66005555056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74625096084).

66005555056 is an abundant number, since it is smaller than the sum of its proper divisors (83244637112).

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

66005555056 is a wasteful number, since it uses less digits than its factorization.

66005555056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274566 (or 274553 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 43.

The spelling of 66005555056 in words is "sixty-six billion, five million, five hundred fifty-five thousand, fifty-six".