66635712601 has 4 divisors (see below), whose sum is σ = 66636324304. Its totient is φ = 66635100900.

The previous prime is 66635712599. The next prime is 66635712623. The reversal of 66635712601 is 10621753666.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 66635712601 - 2¹ = 66635712599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66635712001) 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, 93135 + ... + 376756.

It is an arithmetic number, because the mean of its divisors is an integer number (16659081076).

Almost surely, 2^66635712601 is an apocalyptic number.

It is an amenable number.

66635712601 is a deficient number, since it is larger than the sum of its proper divisors (611703).

66635712601 is a wasteful number, since it uses less digits than its factorization.

66635712601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611702.

The product of its (nonzero) digits is 272160, while the sum is 43.

The spelling of 66635712601 in words is "sixty-six billion, six hundred thirty-five million, seven hundred twelve thousand, six hundred one".