66798788565600 has 1728 divisors, whose sum is σ = 299719255739904. Its totient is φ = 13623571906560.

The previous prime is 66798788565527. The next prime is 66798788565611. The reversal of 66798788565600 is 656588789766.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 66798788565600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 2732826979 + ... + 2732851421.

It is an arithmetic number, because the mean of its divisors is an integer number (173448643368).

Almost surely, 2^{66798788565600} is an apocalyptic number.

66798788565600 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 66798788565600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149859627869952).

66798788565600 is an abundant number, since it is smaller than the sum of its proper divisors (232920467174304).

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

66798788565600 is a wasteful number, since it uses less digits than its factorization.

66798788565600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24629 (or 24613 counting only the distinct ones).

The product of its (nonzero) digits is 7315660800, while the sum is 81.

The spelling of 66798788565600 in words is "sixty-six trillion, seven hundred ninety-eight billion, seven hundred eighty-eight million, five hundred sixty-five thousand, six hundred".