66297681216 has 168 divisors, whose sum is σ = 204791889120. Its totient is φ = 20384953344.

The previous prime is 66297681211. The next prime is 66297681221. The reversal of 66297681216 is 61218679266.

66297681216 is a `hidden beast` number, since 6 + 629 + 7 + 6 + 8 + 1 + 2 + 1 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (66297681211) and next prime (66297681221).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66297681211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16494055 + ... + 16498073.

It is an arithmetic number, because the mean of its divisors is an integer number (1218999340).

Almost surely, 2^66297681216 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 66297681216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102395944560).

66297681216 is an abundant number, since it is smaller than the sum of its proper divisors (138494207904).

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

66297681216 is a wasteful number, since it uses less digits than its factorization.

66297681216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6253 (or 6240 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The spelling of 66297681216 in words is "sixty-six billion, two hundred ninety-seven million, six hundred eighty-one thousand, two hundred sixteen".