4215221 has 2 divisors, whose sum is σ = 4215222. Its totient is φ = 4215220.

The previous prime is 4215217. The next prime is 4215227. The reversal of 4215221 is 1225124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2283121 + 1932100 = 1511^2 + 1390^2 .

It is a cyclic number.

It is not a de Polignac number, because 4215221 - 2² = 4215217 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 4215221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4215227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2107610 + 2107611.

It is an arithmetic number, because the mean of its divisors is an integer number (2107611).

Almost surely, 2^4215221 is an apocalyptic number.

It is an amenable number.

4215221 is a deficient number, since it is larger than the sum of its proper divisors (1).

4215221 is an equidigital number, since it uses as much as digits as its factorization.

4215221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 160, while the sum is 17.

The square root of 4215221 is about 2053.1003385125. The cubic root of 4215221 is about 161.5375343688.

The spelling of 4215221 in words is "four million, two hundred fifteen thousand, two hundred twenty-one".