66198765568 has 204 divisors, whose sum is σ = 147753716880. Its totient is φ = 29628039168.

The previous prime is 66198765557. The next prime is 66198765601. The reversal of 66198765568 is 86556789166.

Its product of digits (130636800) is a multiple of the sum of its prime factors (240).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 476250043 + ... + 476250181.

Almost surely, 2^66198765568 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 66198765568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73876858440).

66198765568 is an abundant number, since it is smaller than the sum of its proper divisors (81554951312).

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

66198765568 is an equidigital number, since it uses as much as digits as its factorization.

66198765568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 197 counting only the distinct ones).

The product of its digits is 130636800, while the sum is 67.

The spelling of 66198765568 in words is "sixty-six billion, one hundred ninety-eight million, seven hundred sixty-five thousand, five hundred sixty-eight".