66201768557 has 4 divisors (see below), whose sum is σ = 66234888000. Its totient is φ = 66168649116.

The previous prime is 66201768547. The next prime is 66201768587. The reversal of 66201768557 is 75586710266.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66201768557 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66201768499 and 66201768508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66201768517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16556723 + ... + 16560720.

It is an arithmetic number, because the mean of its divisors is an integer number (16558722000).

Almost surely, 2^66201768557 is an apocalyptic number.

It is an amenable number.

66201768557 is a deficient number, since it is larger than the sum of its proper divisors (33119443).

66201768557 is a wasteful number, since it uses less digits than its factorization.

66201768557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33119442.

The product of its (nonzero) digits is 4233600, while the sum is 53.

The spelling of 66201768557 in words is "sixty-six billion, two hundred one million, seven hundred sixty-eight thousand, five hundred fifty-seven".