66489929661312 has 640 divisors, whose sum is σ = 207604035555840. Its totient is φ = 21103140667392.

The previous prime is 66489929661271. The next prime is 66489929661317. The reversal of 66489929661312 is 21316692998466.

66489929661312 is a `hidden beast` number, since 6 + 6 + 4 + 89 + 92 + 96 + 61 + 312 = 666.

66489929661312 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66489929661312² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66489929661317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5385101923 + ... + 5385114269.

It is an arithmetic number, because the mean of its divisors is an integer number (324381305556).

Almost surely, 2^{66489929661312} 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 66489929661312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103802017777920).

66489929661312 is an abundant number, since it is smaller than the sum of its proper divisors (141114105894528).

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

66489929661312 is a wasteful number, since it uses less digits than its factorization.

66489929661312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12720 (or 12699 counting only the distinct ones).

The product of its digits is 362797056, while the sum is 72.

The spelling of 66489929661312 in words is "sixty-six trillion, four hundred eighty-nine billion, nine hundred twenty-nine million, six hundred sixty-one thousand, three hundred twelve".