66709917888 has 224 divisors, whose sum is σ = 185817784320. Its totient is φ = 21100584960.

The previous prime is 66709917887. The next prime is 66709917917. The reversal of 66709917888 is 88871990766.

It is not an unprimeable number, because it can be changed into a prime (66709917887) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 52985803 + ... + 52987061.

It is an arithmetic number, because the mean of its divisors is an integer number (829543680).

Almost surely, 2^66709917888 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 66709917888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92908892160).

66709917888 is an abundant number, since it is smaller than the sum of its proper divisors (119107866432).

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

66709917888 is a wasteful number, since it uses less digits than its factorization.

66709917888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1495 (or 1485 counting only the distinct ones).

The product of its (nonzero) digits is 73156608, while the sum is 69.

The spelling of 66709917888 in words is "sixty-six billion, seven hundred nine million, nine hundred seventeen thousand, eight hundred eighty-eight".