66881347720 has 64 divisors (see below), whose sum is σ = 164443608000. Its totient is φ = 24278964480.

The previous prime is 66881347717. The next prime is 66881347739. The reversal of 66881347720 is 2774318866.

It is a super-2 number, since 2×66881347720² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128806 + ... + 387754.

It is an arithmetic number, because the mean of its divisors is an integer number (2569431375).

Almost surely, 2^66881347720 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 66881347720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82221804000).

66881347720 is an abundant number, since it is smaller than the sum of its proper divisors (97562260280).

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

66881347720 is a wasteful number, since it uses less digits than its factorization.

66881347720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259558 (or 259554 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 52.

The spelling of 66881347720 in words is "sixty-six billion, eight hundred eighty-one million, three hundred forty-seven thousand, seven hundred twenty".