221444121 has 4 divisors (see below), whose sum is σ = 295258832. Its totient is φ = 147629412.

The previous prime is 221444099. The next prime is 221444131. The reversal of 221444121 is 121444122.

221444121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221444121 - 2¹¹ = 221442073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221444131) 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, 36907351 + ... + 36907356.

It is an arithmetic number, because the mean of its divisors is an integer number (73814708).

Almost surely, 2^221444121 is an apocalyptic number.

It is an amenable number.

221444121 is a deficient number, since it is larger than the sum of its proper divisors (73814711).

221444121 is an equidigital number, since it uses as much as digits as its factorization.

221444121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73814710.

The product of its digits is 512, while the sum is 21.

The square root of 221444121 is about 14880.9986560042. The cubic root of 221444121 is about 604.9990856713. Note that the first 3 decimals are identical.

Adding to 221444121 its reverse (121444122), we get a palindrome (342888243).

Subtracting from 221444121 its reverse (121444122), we obtain a palindrome (99999999).

The spelling of 221444121 in words is "two hundred twenty-one million, four hundred forty-four thousand, one hundred twenty-one".