66631788864 has 448 divisors, whose sum is σ = 225425203200. Its totient is φ = 19160064000.

The previous prime is 66631788851. The next prime is 66631788869. The reversal of 66631788864 is 46888713666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66631788869) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17300539 + ... + 17304389.

Almost surely, 2^66631788864 is an apocalyptic number.

66631788864 is a gapful number since it is divisible by the number (64) 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 66631788864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112712601600).

66631788864 is an abundant number, since it is smaller than the sum of its proper divisors (158793414336).

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

66631788864 is a wasteful number, since it uses less digits than its factorization.

66631788864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3939 (or 3923 counting only the distinct ones).

The product of its digits is 55738368, while the sum is 63.

The spelling of 66631788864 in words is "sixty-six billion, six hundred thirty-one million, seven hundred eighty-eight thousand, eight hundred sixty-four".