66981560576 has 216 divisors, whose sum is σ = 160618161816. Its totient is φ = 27776286720.

The previous prime is 66981560473. The next prime is 66981560603. The reversal of 66981560576 is 67506518966.

It can be written as a sum of positive squares in 4 ways, for example, as 7093682176 + 59887878400 = 84224^2 + 244720^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128563196 + ... + 128563716.

It is an arithmetic number, because the mean of its divisors is an integer number (743602601).

Almost surely, 2^66981560576 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 66981560576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80309080908).

66981560576 is an abundant number, since it is smaller than the sum of its proper divisors (93636601240).

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

66981560576 is a wasteful number, since it uses less digits than its factorization.

66981560576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 16329600, while the sum is 59.

The spelling of 66981560576 in words is "sixty-six billion, nine hundred eighty-one million, five hundred sixty thousand, five hundred seventy-six".