11221121222221 has 4 divisors (see below), whose sum is σ = 11332221432444. Its totient is φ = 11110021012000.

The previous prime is 11221121222191. The next prime is 11221121222243. The reversal of 11221121222221 is 12222212112211.

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 5179288398025 + 6041832824196 = 2275805^2 + 2458014^2 .

It is a cyclic number.

It is not a de Polignac number, because 11221121222221 - 2⁵ = 11221121222189 is a prime.

It is a super-2 number, since 2×11221121222221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11221121222192 and 11221121222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11221121222321) 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 3 ways as a sum of consecutive naturals, for example, 55550104960 + ... + 55550105161.

It is an arithmetic number, because the mean of its divisors is an integer number (2833055358111).

Almost surely, 2^{11221121222221} is an apocalyptic number.

It is an amenable number.

11221121222221 is a deficient number, since it is larger than the sum of its proper divisors (111100210223).

11221121222221 is a wasteful number, since it uses less digits than its factorization.

11221121222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111100210222.

The product of its digits is 256, while the sum is 22.

Adding to 11221121222221 its reverse (12222212112211), we get a palindrome (23443333334432).

The spelling of 11221121222221 in words is "eleven trillion, two hundred twenty-one billion, one hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".