66654031640 has 96 divisors (see below), whose sum is σ = 174563722080. Its totient is φ = 22838796288.

The previous prime is 66654031627. The next prime is 66654031679. The reversal of 66654031640 is 4613045666.

It is a super-2 number, since 2×66654031640² (a number of 22 digits) contains 22 as substring.

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 23 ways as a sum of consecutive naturals, for example, 3485144 + ... + 3504216.

It is an arithmetic number, because the mean of its divisors is an integer number (1818372105).

Almost surely, 2^66654031640 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 66654031640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87281861040).

66654031640 is an abundant number, since it is smaller than the sum of its proper divisors (107909690440).

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

66654031640 is a wasteful number, since it uses less digits than its factorization.

66654031640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20881 (or 20870 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 41.

The spelling of 66654031640 in words is "sixty-six billion, six hundred fifty-four million, thirty-one thousand, six hundred forty".