66604915873 has 4 divisors (see below), whose sum is σ = 68901637140. Its totient is φ = 64308194608.

The previous prime is 66604915837. The next prime is 66604915877. The reversal of 66604915873 is 37851940666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42396045409 + 24208870464 = 205903^2 + 155592^2 .

It is a de Polignac number, because none of the positive numbers 2^k-66604915873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66604915877) 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 3 ways as a sum of consecutive naturals, for example, 1148360590 + ... + 1148360647.

It is an arithmetic number, because the mean of its divisors is an integer number (17225409285).

Almost surely, 2^66604915873 is an apocalyptic number.

It is an amenable number.

66604915873 is a deficient number, since it is larger than the sum of its proper divisors (2296721267).

66604915873 is a wasteful number, since it uses less digits than its factorization.

66604915873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296721266.

The product of its (nonzero) digits is 6531840, while the sum is 55.

The spelling of 66604915873 in words is "sixty-six billion, six hundred four million, nine hundred fifteen thousand, eight hundred seventy-three".