66865944960 has 1024 divisors, whose sum is σ = 266499072000. Its totient is φ = 15763636224.

The previous prime is 66865944949. The next prime is 66865945009. The reversal of 66865944960 is 6944956866.

66865944960 is a `hidden beast` number, since 6 + 6 + 86 + 59 + 449 + 60 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 400394797 + ... + 400394963.

It is an arithmetic number, because the mean of its divisors is an integer number (260253000).

Almost surely, 2^66865944960 is an apocalyptic number.

66865944960 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 66865944960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133249536000).

66865944960 is an abundant number, since it is smaller than the sum of its proper divisors (199633127040).

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

66865944960 is a wasteful number, since it uses less digits than its factorization.

66865944960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 67184640, while the sum is 63.

The spelling of 66865944960 in words is "sixty-six billion, eight hundred sixty-five million, nine hundred forty-four thousand, nine hundred sixty".