345221 has 2 divisors, whose sum is σ = 345222.
Its totient is φ = 345220.
The previous prime is 345193. The next prime is 345227. The reversal of 345221 is 122543.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 261121 + 84100 = 511^2 + 290^2
It is a cyclic number.
It is not a de Polignac number, because 345221 - 214 = 328837 is a prime.
It is a Chen prime.
It is a self number, because there is not a number n which added to its sum of digits gives 345221.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (345227) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172610 + 172611.
It is an arithmetic number, because the mean of its divisors is an integer number (172611).
2345221 is an apocalyptic number.
It is an amenable number.
345221 is a deficient number, since it is larger than the sum of its proper divisors (1).
345221 is an equidigital number, since it uses as much as digits as its factorization.
345221 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 240, while the sum is 17.
The square root of 345221 is about 587.5551037988.
Note that the first 3 decimals coincide.
The cubic root of 345221 is about 70.1507634932.
Adding to 345221 its reverse (122543), we get a palindrome (467764).
It can be divided in two parts, 345 and 221, that multiplied together give a triangular number (76245 = T390).
The spelling of 345221 in words is "three hundred forty-five thousand, two hundred twenty-one".