3505220221 has 2 divisors, whose sum is σ = 3505220222. Its totient is φ = 3505220220.

The previous prime is 3505220219. The next prime is 3505220249. The reversal of 3505220221 is 1220225053.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2288187225 + 1217032996 = 47835^2 + 34886^2 .

It is an emirp because it is prime and its reverse (1220225053) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3505220221 - 2¹ = 3505220219 is a prime.

Together with 3505220219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 3505220192 and 3505220201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3505220921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1752610110 + 1752610111.

It is an arithmetic number, because the mean of its divisors is an integer number (1752610111).

Almost surely, 2^3505220221 is an apocalyptic number.

It is an amenable number.

3505220221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3505220221 is an equidigital number, since it uses as much as digits as its factorization.

3505220221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 3505220221 is about 59204.9003123897. The cubic root of 3505220221 is about 1519.0489521839.

Adding to 3505220221 its reverse (1220225053), we get a palindrome (4725445274).

The spelling of 3505220221 in words is "three billion, five hundred five million, two hundred twenty thousand, two hundred twenty-one".