66786115680 has 768 divisors, whose sum is σ = 271985817600. Its totient is φ = 15182069760.

The previous prime is 66786115679. The next prime is 66786115709. The reversal of 66786115680 is 8651168766.

66786115680 is a `hidden beast` number, since 6 + 6 + 78 + 6 + 1 + 1 + 568 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 32092240 + ... + 32094320.

It is an arithmetic number, because the mean of its divisors is an integer number (354148200).

Almost surely, 2^66786115680 is an apocalyptic number.

66786115680 is a gapful number since it is divisible by the number (60) 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 66786115680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135992908800).

66786115680 is an abundant number, since it is smaller than the sum of its proper divisors (205199701920).

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

66786115680 is a wasteful number, since it uses less digits than its factorization.

66786115680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2164 (or 2150 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 66786115680 in words is "sixty-six billion, seven hundred eighty-six million, one hundred fifteen thousand, six hundred eighty".