66604923839 has 4 divisors (see below), whose sum is σ = 66610200456. Its totient is φ = 66599647224.

The previous prime is 66604923797. The next prime is 66604923851. The reversal of 66604923839 is 93832940666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66604923839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66604920839) 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, 2619329 + ... + 2644634.

It is an arithmetic number, because the mean of its divisors is an integer number (16652550114).

Almost surely, 2^66604923839 is an apocalyptic number.

66604923839 is a deficient number, since it is larger than the sum of its proper divisors (5276617).

66604923839 is a wasteful number, since it uses less digits than its factorization.

66604923839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5276616.

The product of its (nonzero) digits is 10077696, while the sum is 56.

The spelling of 66604923839 in words is "sixty-six billion, six hundred four million, nine hundred twenty-three thousand, eight hundred thirty-nine".