221121112221 has 64 divisors (see below), whose sum is σ = 342047059200. Its totient is φ = 141055229952.

The previous prime is 221121112211. The next prime is 221121112279. The reversal of 221121112221 is 122211121122.

221121112221 is a `hidden beast` number, since 221 + 1 + 211 + 12 + 221 = 666.

It is not a de Polignac number, because 221121112221 - 2¹⁴ = 221121095837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221121112194 and 221121112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121112211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 47316541 + ... + 47321213.

It is an arithmetic number, because the mean of its divisors is an integer number (5344485300).

Almost surely, 2^221121112221 is an apocalyptic number.

It is an amenable number.

221121112221 is a deficient number, since it is larger than the sum of its proper divisors (120925946979).

221121112221 is a wasteful number, since it uses less digits than its factorization.

221121112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5547 (or 5541 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 221121112221 its reverse (122211121122), we get a palindrome (343332233343).

The spelling of 221121112221 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred twelve thousand, two hundred twenty-one".