2101222165221 has 12 divisors (see below), whose sum is σ = 3076675378348. Its totient is φ = 1381625532864.

The previous prime is 2101222165201. The next prime is 2101222165261. The reversal of 2101222165221 is 1225612221012.

2101222165221 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 2 + 2 + 2 + 1 + 652 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1794959537121 + 306262628100 = 1339761^2 + 553410^2 .

It is not a de Polignac number, because 2101222165221 - 2⁹ = 2101222164709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101222165201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1599102970 + ... + 1599104283.

Almost surely, 2^{2101222165221} is an apocalyptic number.

It is an amenable number.

2101222165221 is a deficient number, since it is larger than the sum of its proper divisors (975453213127).

2101222165221 is a wasteful number, since it uses less digits than its factorization.

2101222165221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3198207332 (or 3198207329 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

Adding to 2101222165221 its reverse (1225612221012), we get a palindrome (3326834386233).

The spelling of 2101222165221 in words is "two trillion, one hundred one billion, two hundred twenty-two million, one hundred sixty-five thousand, two hundred twenty-one".