405221 has 2 divisors, whose sum is σ = 405222. Its totient is φ = 405220.

The previous prime is 405211. The next prime is 405227. The reversal of 405221 is 122504.

405221 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 348100 + 57121 = 590^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 405221 - 2⁶ = 405157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 405196 and 405205.

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 405221.

It is not a weakly prime, because it can be changed into another prime (405227) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202610 + 202611.

It is an arithmetic number, because the mean of its divisors is an integer number (202611).

2⁴⁰⁵²²¹ is an apocalyptic number.

It is an amenable number.

405221 is a deficient number, since it is larger than the sum of its proper divisors (1).

405221 is an equidigital number, since it uses as much as digits as its factorization.

405221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 405221 is about 636.5697133857. The cubic root of 405221 is about 73.9998173845. Note that the first 3 decimals are identical.

Adding to 405221 its reverse (122504), we get a palindrome (527725).

It can be divided in two parts, 405 and 221, that added together give a palindrome (626).

The spelling of 405221 in words is "four hundred five thousand, two hundred twenty-one".