66515772608 has 56 divisors (see below), whose sum is σ = 136127947200. Its totient is φ = 32223356928.

The previous prime is 66515772601. The next prime is 66515772623. The reversal of 66515772608 is 80627751566.

It is a self number, because there is not a number n which added to its sum of digits gives 66515772608.

It is not an unprimeable number, because it can be changed into a prime (66515772601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 507188 + ... + 624716.

It is an arithmetic number, because the mean of its divisors is an integer number (2430856200).

Almost surely, 2^66515772608 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 66515772608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68063973600).

66515772608 is an abundant number, since it is smaller than the sum of its proper divisors (69612174592).

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

66515772608 is a wasteful number, since it uses less digits than its factorization.

66515772608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117817 (or 117807 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 53.

The spelling of 66515772608 in words is "sixty-six billion, five hundred fifteen million, seven hundred seventy-two thousand, six hundred eight".