66176012020561 has 4 divisors (see below), whose sum is σ = 66190155220800. Its totient is φ = 66161868820324.

The previous prime is 66176012020529. The next prime is 66176012020567. The reversal of 66176012020561 is 16502021067166.

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 66176012020561 - 2⁵ = 66176012020529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66176012020567) 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, 7071593101 + ... + 7071602458.

It is an arithmetic number, because the mean of its divisors is an integer number (16547538805200).

Almost surely, 2^{66176012020561} is an apocalyptic number.

It is an amenable number.

66176012020561 is a deficient number, since it is larger than the sum of its proper divisors (14143200239).

66176012020561 is a wasteful number, since it uses less digits than its factorization.

66176012020561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14143200238.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 66176012020561 in words is "sixty-six trillion, one hundred seventy-six billion, twelve million, twenty thousand, five hundred sixty-one".