66488520809 has 4 divisors (see below), whose sum is σ = 66492339600. Its totient is φ = 66484702020.

The previous prime is 66488520781. The next prime is 66488520817. The reversal of 66488520809 is 90802588466.

66488520809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66488520809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66488525809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1883159 + ... + 1918140.

It is an arithmetic number, because the mean of its divisors is an integer number (16623084900).

Almost surely, 2^66488520809 is an apocalyptic number.

It is an amenable number.

66488520809 is a deficient number, since it is larger than the sum of its proper divisors (3818791).

66488520809 is a wasteful number, since it uses less digits than its factorization.

66488520809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3818790.

The product of its (nonzero) digits is 6635520, while the sum is 56.

The spelling of 66488520809 in words is "sixty-six billion, four hundred eighty-eight million, five hundred twenty thousand, eight hundred nine".