666556115500 has 192 divisors, whose sum is σ = 1606993105536. Its totient is φ = 239510400000.

The previous prime is 666556115431. The next prime is 666556115501. The reversal of 666556115500 is 5511655666.

666556115500 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×666556115500³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (666556115501) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 407180682 + ... + 407182318.

It is an arithmetic number, because the mean of its divisors is an integer number (8369755758).

Almost surely, 2^666556115500 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 666556115500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (803496552768).

666556115500 is an abundant number, since it is smaller than the sum of its proper divisors (940436990036).

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

666556115500 is a wasteful number, since it uses less digits than its factorization.

666556115500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2501 (or 2489 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 46.

It can be divided in two parts, 6665 and 56115500, that added together give a palindrome (56122165).

The spelling of 666556115500 in words is "six hundred sixty-six billion, five hundred fifty-six million, one hundred fifteen thousand, five hundred".