1724221 has 2 divisors, whose sum is σ = 1724222. Its totient is φ = 1724220.

The previous prime is 1724209. The next prime is 1724227. The reversal of 1724221 is 1224271.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1625625 + 98596 = 1275^2 + 314^2 .

It is an emirp because it is prime and its reverse (1224271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1724221 - 2¹¹ = 1722173 is a prime.

It is a super-3 number, since 3×1724221³ = 15378006687913337583, which contains 333 as substring.

It is a Chen prime.

1724221 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1724227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 862110 + 862111.

It is an arithmetic number, because the mean of its divisors is an integer number (862111).

2^1724221 is an apocalyptic number.

It is an amenable number.

1724221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1724221 is an equidigital number, since it uses as much as digits as its factorization.

1724221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 224, while the sum is 19.

The square root of 1724221 is about 1313.0959599359. The cubic root of 1724221 is about 119.9124593022.

Adding to 1724221 its reverse (1224271), we get a palindrome (2948492).

The spelling of 1724221 in words is "one million, seven hundred twenty-four thousand, two hundred twenty-one".