221335421 has 2 divisors, whose sum is σ = 221335422. Its totient is φ = 221335420.

The previous prime is 221335391. The next prime is 221335441. The reversal of 221335421 is 124533122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204204100 + 17131321 = 14290^2 + 4139^2 .

It is a cyclic number.

It is not a de Polignac number, because 221335421 - 2¹⁴ = 221319037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221335441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110667710 + 110667711.

It is an arithmetic number, because the mean of its divisors is an integer number (110667711).

Almost surely, 2^221335421 is an apocalyptic number.

It is an amenable number.

221335421 is a deficient number, since it is larger than the sum of its proper divisors (1).

221335421 is an equidigital number, since it uses as much as digits as its factorization.

221335421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 23.

The square root of 221335421 is about 14877.3458990507. The cubic root of 221335421 is about 604.9000777535.

Adding to 221335421 its reverse (124533122), we get a palindrome (345868543).

The spelling of 221335421 in words is "two hundred twenty-one million, three hundred thirty-five thousand, four hundred twenty-one".