66636349613 has 4 divisors (see below), whose sum is σ = 67247692380. Its totient is φ = 66025006848.

The previous prime is 66636349609. The next prime is 66636349667. The reversal of 66636349613 is 31694363666.

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 29472992329 + 37163357284 = 171677^2 + 192778^2 .

It is a cyclic number.

It is not a de Polignac number, because 66636349613 - 2² = 66636349609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66636349673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 305671220 + ... + 305671437.

It is an arithmetic number, because the mean of its divisors is an integer number (16811923095).

Almost surely, 2^66636349613 is an apocalyptic number.

It is an amenable number.

66636349613 is a deficient number, since it is larger than the sum of its proper divisors (611342767).

66636349613 is a wasteful number, since it uses less digits than its factorization.

66636349613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611342766.

The product of its digits is 7558272, while the sum is 53.

The spelling of 66636349613 in words is "sixty-six billion, six hundred thirty-six million, three hundred forty-nine thousand, six hundred thirteen".