18666885505536 has 240 divisors, whose sum is σ = 56762060674176. Its totient is φ = 5893973065728.

The previous prime is 18666885505529. The next prime is 18666885505549. The reversal of 18666885505536 is 63550558866681.

It is a happy number.

It is a super-2 number, since 2×18666885505536² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10061356 + ... + 11771348.

Almost surely, 2^{18666885505536} is an apocalyptic number.

18666885505536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18666885505536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28381030337088).

18666885505536 is an abundant number, since it is smaller than the sum of its proper divisors (38095175168640).

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

18666885505536 is a wasteful number, since it uses less digits than its factorization.

18666885505536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710143 (or 1710124 counting only the distinct ones).

The product of its (nonzero) digits is 1244160000, while the sum is 72.

The spelling of 18666885505536 in words is "eighteen trillion, six hundred sixty-six billion, eight hundred eighty-five million, five hundred five thousand, five hundred thirty-six".