7500221 has 2 divisors, whose sum is σ = 7500222. Its totient is φ = 7500220.

The previous prime is 7500217. The next prime is 7500223. The reversal of 7500221 is 1220057.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6528025 + 972196 = 2555^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 7500221 - 2² = 7500217 is a prime.

Together with 7500223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7500221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7500223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3750110 + 3750111.

It is an arithmetic number, because the mean of its divisors is an integer number (3750111).

Almost surely, 2^7500221 is an apocalyptic number.

It is an amenable number.

7500221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7500221 is an equidigital number, since it uses as much as digits as its factorization.

7500221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 7500221 is about 2738.6531361237. The cubic root of 7500221 is about 195.7453046746.

Adding to 7500221 its reverse (1220057), we get a palindrome (8720278).

The spelling of 7500221 in words is "seven million, five hundred thousand, two hundred twenty-one".