2220166660561 has 4 divisors (see below), whose sum is σ = 2220177872052. Its totient is φ = 2220155449072.

The previous prime is 2220166660559. The next prime is 2220166660609. The reversal of 2220166660561 is 1650666610222.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 558130020561 + 1662036640000 = 747081^2 + 1289200^2 .

It is a cyclic number.

It is not a de Polignac number, because 2220166660561 - 2¹ = 2220166660559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2220166666561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5303266 + ... + 5706571.

It is an arithmetic number, because the mean of its divisors is an integer number (555044468013).

Almost surely, 2^{2220166660561} is an apocalyptic number.

It is an amenable number.

2220166660561 is a deficient number, since it is larger than the sum of its proper divisors (11211491).

2220166660561 is a wasteful number, since it uses less digits than its factorization.

2220166660561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11211490.

The product of its (nonzero) digits is 311040, while the sum is 43.

The spelling of 2220166660561 in words is "two trillion, two hundred twenty billion, one hundred sixty-six million, six hundred sixty thousand, five hundred sixty-one".