2102211201221 has 4 divisors (see below), whose sum is σ = 2102216156172. Its totient is φ = 2102206246272.

The previous prime is 2102211201203. The next prime is 2102211201227. The reversal of 2102211201221 is 1221021122012.

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 649007472100 + 1453203729121 = 805610^2 + 1205489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2102211201221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2102211201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2102211201227) 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, 1774610 + ... + 2711763.

It is an arithmetic number, because the mean of its divisors is an integer number (525554039043).

Almost surely, 2^{2102211201221} is an apocalyptic number.

It is an amenable number.

2102211201221 is a deficient number, since it is larger than the sum of its proper divisors (4954951).

2102211201221 is an equidigital number, since it uses as much as digits as its factorization.

2102211201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4954950.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2102211201221 its reverse (1221021122012), we get a palindrome (3323232323233).

The spelling of 2102211201221 in words is "two trillion, one hundred two billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".