66809842576 has 75 divisors (see below), whose sum is σ = 137402942411. Its totient is φ = 31469969952.

The previous prime is 66809842573. The next prime is 66809842609. The reversal of 66809842576 is 67524890866.

The square root of 66809842576 is 258476.

It is a perfect power (a square), and thus also a powerful number.

66809842576 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66809842573) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 373239255 + ... + 373239433.

Almost surely, 2^66809842576 is an apocalyptic number.

66809842576 is the 258476-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66809842576

66809842576 is an abundant number, since it is smaller than the sum of its proper divisors (70593099835).

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

66809842576 is an frugal number, since it uses more digits than its factorization.

66809842576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 61.

The spelling of 66809842576 in words is "sixty-six billion, eight hundred nine million, eight hundred forty-two thousand, five hundred seventy-six".