66516587760 has 640 divisors, whose sum is σ = 258683443200. Its totient is φ = 13795246080.

The previous prime is 66516587729. The next prime is 66516587783. The reversal of 66516587760 is 6778561566.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a self number, because there is not a number n which added to its sum of digits gives 66516587760.

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, 167547882 + ... + 167548278.

It is an arithmetic number, because the mean of its divisors is an integer number (404192880).

Almost surely, 2^66516587760 is an apocalyptic number.

66516587760 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 66516587760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129341721600).

66516587760 is an abundant number, since it is smaller than the sum of its proper divisors (192166855440).

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

66516587760 is a wasteful number, since it uses less digits than its factorization.

66516587760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 12700800, while the sum is 57.

The spelling of 66516587760 in words is "sixty-six billion, five hundred sixteen million, five hundred eighty-seven thousand, seven hundred sixty".