66516773356800 has 1512 divisors, whose sum is σ = 267050958469400. Its totient is φ = 16298456186880.

The previous prime is 66516773356777. The next prime is 66516773356849. The reversal of 66516773356800 is 865337761566.

66516773356800 is a `hidden beast` number, since 6 + 6 + 5 + 1 + 67 + 7 + 3 + 3 + 568 + 0 + 0 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 29529747120384 + 36987026236416 = 5434128^2 + 6081696^2 .

It is a super-2 number, since 2×66516773356800² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 13889488806 + ... + 13889493594.

Almost surely, 2^{66516773356800} is an apocalyptic number.

66516773356800 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 66516773356800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133525479234700).

66516773356800 is an abundant number, since it is smaller than the sum of its proper divisors (200534185112600).

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

66516773356800 is a wasteful number, since it uses less digits than its factorization.

66516773356800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5075 (or 5041 counting only the distinct ones).

The product of its (nonzero) digits is 114307200, while the sum is 63.

The spelling of 66516773356800 in words is "sixty-six trillion, five hundred sixteen billion, seven hundred seventy-three million, three hundred fifty-six thousand, eight hundred".