221144321 has 2 divisors, whose sum is σ = 221144322. Its totient is φ = 221144320.

The previous prime is 221144311. The next prime is 221144369. The reversal of 221144321 is 123441122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209207296 + 11937025 = 14464^2 + 3455^2 .

It is a cyclic number.

It is not a de Polignac number, because 221144321 - 2⁶ = 221144257 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221144293 and 221144302.

It is not a weakly prime, because it can be changed into another prime (221144311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110572160 + 110572161.

It is an arithmetic number, because the mean of its divisors is an integer number (110572161).

Almost surely, 2^221144321 is an apocalyptic number.

It is an amenable number.

221144321 is a deficient number, since it is larger than the sum of its proper divisors (1).

221144321 is an equidigital number, since it uses as much as digits as its factorization.

221144321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 20.

The square root of 221144321 is about 14870.9219956262. The cubic root of 221144321 is about 604.7259382977.

Adding to 221144321 its reverse (123441122), we get a palindrome (344585443).

The spelling of 221144321 in words is "two hundred twenty-one million, one hundred forty-four thousand, three hundred twenty-one".