66579712861 has 4 divisors (see below), whose sum is σ = 66640076352. Its totient is φ = 66519349372.

The previous prime is 66579712817. The next prime is 66579712867. The reversal of 66579712861 is 16821797566.

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 66579712861 - 2¹³ = 66579704669 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66579712796 and 66579712805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66579712867) 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, 30180091 + ... + 30182296.

It is an arithmetic number, because the mean of its divisors is an integer number (16660019088).

Almost surely, 2^66579712861 is an apocalyptic number.

It is an amenable number.

66579712861 is a deficient number, since it is larger than the sum of its proper divisors (60363491).

66579712861 is a wasteful number, since it uses less digits than its factorization.

66579712861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60363490.

The product of its digits is 7620480, while the sum is 58.

The spelling of 66579712861 in words is "sixty-six billion, five hundred seventy-nine million, seven hundred twelve thousand, eight hundred sixty-one".