15330221 has 2 divisors, whose sum is σ = 15330222. Its totient is φ = 15330220.

The previous prime is 15330193. The next prime is 15330223. The reversal of 15330221 is 12203351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8497225 + 6832996 = 2915^2 + 2614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15330221 is a prime.

Together with 15330223, 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 15330221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15330223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7665110 + 7665111.

It is an arithmetic number, because the mean of its divisors is an integer number (7665111).

Almost surely, 2^15330221 is an apocalyptic number.

It is an amenable number.

15330221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15330221 is an equidigital number, since it uses as much as digits as its factorization.

15330221 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 17.

The square root of 15330221 is about 3915.3826122105. The cubic root of 15330221 is about 248.4178537080.

Adding to 15330221 its reverse (12203351), we get a palindrome (27533572).

It can be divided in two parts, 15330 and 221, that added together give a palindrome (15551).

The spelling of 15330221 in words is "fifteen million, three hundred thirty thousand, two hundred twenty-one".