66663586640 has 160 divisors (see below), whose sum is σ = 181065196800. Its totient is φ = 22816206336.

The previous prime is 66663586631. The next prime is 66663586673. The reversal of 66663586640 is 4668536666.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18739742 + ... + 18743298.

It is an arithmetic number, because the mean of its divisors is an integer number (1131657480).

Almost surely, 2^66663586640 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 66663586640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90532598400).

66663586640 is an abundant number, since it is smaller than the sum of its proper divisors (114401610160).

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

66663586640 is a wasteful number, since it uses less digits than its factorization.

66663586640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4274 (or 4254 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 56.

The spelling of 66663586640 in words is "sixty-six billion, six hundred sixty-three million, five hundred eighty-six thousand, six hundred forty".