66829639680 has 280 divisors, whose sum is σ = 239593904352. Its totient is φ = 17820352512.

The previous prime is 66829639631. The next prime is 66829639687. The reversal of 66829639680 is 8693692866.

66829639680 is a `hidden beast` number, since 6 + 6 + 82 + 96 + 396 + 80 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66829639687) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3307689 + ... + 3327831.

Almost surely, 2^66829639680 is an apocalyptic number.

66829639680 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 66829639680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119796952176).

66829639680 is an abundant number, since it is smaller than the sum of its proper divisors (172764264672).

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

66829639680 is an equidigital number, since it uses as much as digits as its factorization.

66829639680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20186 (or 20153 counting only the distinct ones).

The product of its (nonzero) digits is 40310784, while the sum is 63.

The spelling of 66829639680 in words is "sixty-six billion, eight hundred twenty-nine million, six hundred thirty-nine thousand, six hundred eighty".