65566550161 has 4 divisors (see below), whose sum is σ = 74933200192. Its totient is φ = 56199900132.

The previous prime is 65566550143. The next prime is 65566550221. The reversal of 65566550161 is 16105566556.

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 65566550161 - 2¹³ = 65566541969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65566550261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4683325005 + ... + 4683325018.

It is an arithmetic number, because the mean of its divisors is an integer number (18733300048).

Almost surely, 2^65566550161 is an apocalyptic number.

It is an amenable number.

65566550161 is a deficient number, since it is larger than the sum of its proper divisors (9366650031).

65566550161 is an equidigital number, since it uses as much as digits as its factorization.

65566550161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9366650030.

The product of its (nonzero) digits is 810000, while the sum is 46.

The spelling of 65566550161 in words is "sixty-five billion, five hundred sixty-six million, five hundred fifty thousand, one hundred sixty-one".