7533221 has 2 divisors, whose sum is σ = 7533222. Its totient is φ = 7533220.

The previous prime is 7533209. The next prime is 7533223. The reversal of 7533221 is 1223357.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7230721 + 302500 = 2689^2 + 550^2 .

It is an emirp because it is prime and its reverse (1223357) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7533221 is a prime.

Together with 7533223, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7533223) 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, 3766610 + 3766611.

It is an arithmetic number, because the mean of its divisors is an integer number (3766611).

Almost surely, 2^7533221 is an apocalyptic number.

It is an amenable number.

7533221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7533221 is an equidigital number, since it uses as much as digits as its factorization.

7533221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 23.

The square root of 7533221 is about 2744.6713828799. The cubic root of 7533221 is about 196.0319693097.

Adding to 7533221 its reverse (1223357), we get a palindrome (8756578).

The spelling of 7533221 in words is "seven million, five hundred thirty-three thousand, two hundred twenty-one".