3530221 has 2 divisors, whose sum is σ = 3530222. Its totient is φ = 3530220.

The previous prime is 3530209. The next prime is 3530227. The reversal of 3530221 is 1220353.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2788900 + 741321 = 1670^2 + 861^2 .

It is an emirp because it is prime and its reverse (1220353) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3530221 is a prime.

3530221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3530195 and 3530204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3530227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1765110 + 1765111.

It is an arithmetic number, because the mean of its divisors is an integer number (1765111).

Almost surely, 2^3530221 is an apocalyptic number.

It is an amenable number.

3530221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3530221 is an equidigital number, since it uses as much as digits as its factorization.

3530221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 3530221 is about 1878.8882351007. Note that the first 3 decimals coincide. The cubic root of 3530221 is about 152.2651909135.

Adding to 3530221 its reverse (1220353), we get a palindrome (4750574).

The spelling of 3530221 in words is "three million, five hundred thirty thousand, two hundred twenty-one".