66446729329680 has 480 divisors, whose sum is σ = 272420264772864. Its totient is φ = 14167921065984.

The previous prime is 66446729329649. The next prime is 66446729329681. The reversal of 66446729329680 is 8692392764466.

66446729329680 is a `hidden beast` number, since 6 + 6 + 4 + 46 + 7 + 293 + 296 + 8 + 0 = 666.

It is a super-2 number, since 2×66446729329680² (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 junction number, because it is equal to n+sod(n) for n = 66446729329599 and 66446729329608.

It is not an unprimeable number, because it can be changed into a prime (66446729329681) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6250327 + ... + 13113353.

Almost surely, 2^{66446729329680} is an apocalyptic number.

66446729329680 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 66446729329680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136210132386432).

66446729329680 is an abundant number, since it is smaller than the sum of its proper divisors (205973535443184).

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

66446729329680 is a wasteful number, since it uses less digits than its factorization.

66446729329680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6863183 (or 6863174 counting only the distinct ones).

The product of its (nonzero) digits is 1128701952, while the sum is 72.

The spelling of 66446729329680 in words is "sixty-six trillion, four hundred forty-six billion, seven hundred twenty-nine million, three hundred twenty-nine thousand, six hundred eighty".