2221121211221 has 8 divisors (see below), whose sum is σ = 2447031830688. Its totient is φ = 1999209010000.

The previous prime is 2221121211203. The next prime is 2221121211233. The reversal of 2221121211221 is 1221121211222.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2221121211221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2221121211193 and 2221121211202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221121210221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 999603395 + ... + 999605616.

It is an arithmetic number, because the mean of its divisors is an integer number (305878978836).

Almost surely, 2^{2221121211221} is an apocalyptic number.

It is an amenable number.

2221121211221 is a deficient number, since it is larger than the sum of its proper divisors (225910619467).

2221121211221 is a wasteful number, since it uses less digits than its factorization.

2221121211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1999209123.

The product of its digits is 128, while the sum is 20.

Adding to 2221121211221 its reverse (1221121211222), we get a palindrome (3442242422443).

Subtracting from 2221121211221 its reverse (1221121211222), we obtain a palindrome (999999999999).

It can be divided in two parts, 2221121 and 211221, that added together give a palindrome (2432342).

The spelling of 2221121211221 in words is "two trillion, two hundred twenty-one billion, one hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".