221121111121 has 8 divisors (see below), whose sum is σ = 221491161320. Its totient is φ = 220751371008.

The previous prime is 221121111109. The next prime is 221121111131. The reversal of 221121111121 is 121111121122.

It can be written as a sum of positive squares in 4 ways, for example, as 114828810496 + 106292300625 = 338864^2 + 326025^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 221121111121 - 2¹³ = 221121102929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221121111095 and 221121111104.

It is not an unprimeable number, because it can be changed into a prime (221121111131) 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, 1372435 + ... + 1525063.

It is an arithmetic number, because the mean of its divisors is an integer number (27686395165).

Almost surely, 2^221121111121 is an apocalyptic number.

It is an amenable number.

221121111121 is a deficient number, since it is larger than the sum of its proper divisors (370050199).

221121111121 is a wasteful number, since it uses less digits than its factorization.

221121111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155043.

The product of its digits is 16, while the sum is 16.

Adding to 221121111121 its reverse (121111121122), we get a palindrome (342232232243).

The spelling of 221121111121 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred eleven thousand, one hundred twenty-one".