66521539488 has 96 divisors (see below), whose sum is σ = 179115874560. Its totient is φ = 21606958080.

The previous prime is 66521539453. The next prime is 66521539543. The reversal of 66521539488 is 88493512566.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1001058 + ... + 1065438.

It is an arithmetic number, because the mean of its divisors is an integer number (1865790360).

Almost surely, 2^66521539488 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 66521539488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89557937280).

66521539488 is an abundant number, since it is smaller than the sum of its proper divisors (112594335072).

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

66521539488 is a wasteful number, since it uses less digits than its factorization.

66521539488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64670 (or 64662 counting only the distinct ones).

The product of its digits is 12441600, while the sum is 57.

The spelling of 66521539488 in words is "sixty-six billion, five hundred twenty-one million, five hundred thirty-nine thousand, four hundred eighty-eight".