66573740557 has 4 divisors (see below), whose sum is σ = 69468251040. Its totient is φ = 63679230076.

The previous prime is 66573740491. The next prime is 66573740587. The reversal of 66573740557 is 75504737566.

It is a happy number.

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 not a de Polignac number, because 66573740557 - 2²³ = 66565351949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66573740498 and 66573740507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66573740587) 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, 1447255207 + ... + 1447255252.

It is an arithmetic number, because the mean of its divisors is an integer number (17367062760).

Almost surely, 2^66573740557 is an apocalyptic number.

It is an amenable number.

66573740557 is a deficient number, since it is larger than the sum of its proper divisors (2894510483).

66573740557 is a wasteful number, since it uses less digits than its factorization.

66573740557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2894510482.

The product of its (nonzero) digits is 18522000, while the sum is 55.

The spelling of 66573740557 in words is "sixty-six billion, five hundred seventy-three million, seven hundred forty thousand, five hundred fifty-seven".