6221 has 2 divisors, whose sum is σ = 6222.
Its totient is φ = 6220.
The previous prime is 6217. The next prime is 6229. The reversal of 6221 is 1226.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 3721 + 2500 = 61^2 + 50^2
It is a cyclic number.
It is not a de Polignac number, because 6221 - 22 = 6217 is a prime.
It is a plaindrome in base 6.
It is a nialpdrome in base 10.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 6221.
It is not a weakly prime, because it can be changed into another prime (6229) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3110 + 3111.
It is an arithmetic number, because the mean of its divisors is an integer number (3111).
26221 is an apocalyptic number.
It is an amenable number.
6221 is a deficient number, since it is larger than the sum of its proper divisors (1).
6221 is an equidigital number, since it uses as much as digits as its factorization.
6221 is an evil number, because the sum of its binary digits is even.
The product of its digits is 24, while the sum is 11.
The square root of 6221 is about 78.8733161468.
The cubic root of 6221 is about 18.3916234714.
Adding to 6221 its reverse (1226), we get a palindrome (7447).
It can be divided in two parts, 6 and 221, that multiplied together give a triangular number (1326 = T51).
The spelling of 6221 in words is "six thousand, two hundred twenty-one".