221311 has 2 divisors, whose sum is σ = 221312. Its totient is φ = 221310.

The previous prime is 221303. The next prime is 221317. The reversal of 221311 is 113122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221311 - 2³ = 221303 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110655 + 110656.

It is an arithmetic number, because the mean of its divisors is an integer number (110656).

2²²¹³¹¹ is an apocalyptic number.

221311 is a deficient number, since it is larger than the sum of its proper divisors (1).

221311 is an equidigital number, since it uses as much as digits as its factorization.

221311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12, while the sum is 10.

The square root of 221311 is about 470.4370308554. The cubic root of 221311 is about 60.4877829758.

Adding to 221311 its reverse (113122), we get a palindrome (334433).

The spelling of 221311 in words is "two hundred twenty-one thousand, three hundred eleven", and thus it is an iban number.