221122121220221 has 4 divisors (see below), whose sum is σ = 238131515160252. Its totient is φ = 204112727280192.

The previous prime is 221122121220181. The next prime is 221122121220251. The reversal of 221122121220221 is 122022121221122.

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 21363161320900 + 199758959899321 = 4622030^2 + 14133611^2 .

It is a cyclic number.

It is not a de Polignac number, because 221122121220221 - 2⁴² = 216724074709117 is a prime.

It is a super-3 number, since 3×221122121220221³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221122121220251) 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, 8504696969996 + ... + 8504696970021.

It is an arithmetic number, because the mean of its divisors is an integer number (59532878790063).

Almost surely, 2^{221122121220221} is an apocalyptic number.

It is an amenable number.

221122121220221 is a deficient number, since it is larger than the sum of its proper divisors (17009393940031).

221122121220221 is a wasteful number, since it uses less digits than its factorization.

221122121220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17009393940030.

The product of its (nonzero) digits is 512, while the sum is 23.

Adding to 221122121220221 its reverse (122022121221122), we get a palindrome (343144242441343).

Subtracting from 221122121220221 its reverse (122022121221122), we obtain a palindrome (99099999999099).

The spelling of 221122121220221 in words is "two hundred twenty-one trillion, one hundred twenty-two billion, one hundred twenty-one million, two hundred twenty thousand, two hundred twenty-one".