66109670388864 has 1536 divisors, whose sum is σ = 221331286425600. Its totient is φ = 18825766502400.

The previous prime is 66109670388859. The next prime is 66109670388899. The reversal of 66109670388864 is 46888307690166.

66109670388864 is a `hidden beast` number, since 6 + 6 + 10 + 96 + 70 + 388 + 86 + 4 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 66109670388792 and 66109670388801.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 212571287269 + ... + 212571287579.

It is an arithmetic number, because the mean of its divisors is an integer number (144095889600).

Almost surely, 2^{66109670388864} is an apocalyptic number.

66109670388864 is a gapful number since it is divisible by the number (64) 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 66109670388864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110665643212800).

66109670388864 is an abundant number, since it is smaller than the sum of its proper divisors (155221616036736).

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

66109670388864 is a wasteful number, since it uses less digits than its factorization.

66109670388864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 501645312, while the sum is 72.

The spelling of 66109670388864 in words is "sixty-six trillion, one hundred nine billion, six hundred seventy million, three hundred eighty-eight thousand, eight hundred sixty-four".