66715610721 has 8 divisors (see below), whose sum is σ = 92821719360. Its totient is φ = 42543287952.

The previous prime is 66715610653. The next prime is 66715610743. The reversal of 66715610721 is 12701651766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66715610721 - 2⁷ = 66715610593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66715610771) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 483446386 + ... + 483446523.

It is an arithmetic number, because the mean of its divisors is an integer number (11602714920).

Almost surely, 2^66715610721 is an apocalyptic number.

It is an amenable number.

66715610721 is a deficient number, since it is larger than the sum of its proper divisors (26106108639).

66715610721 is a wasteful number, since it uses less digits than its factorization.

66715610721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 966892935.

The product of its (nonzero) digits is 105840, while the sum is 42.

The spelling of 66715610721 in words is "sixty-six billion, seven hundred fifteen million, six hundred ten thousand, seven hundred twenty-one".