15219221 has 2 divisors, whose sum is σ = 15219222. Its totient is φ = 15219220.

The previous prime is 15219163. The next prime is 15219293. The reversal of 15219221 is 12291251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11662225 + 3556996 = 3415^2 + 1886^2 .

It is a cyclic number.

It is not a de Polignac number, because 15219221 - 2⁶ = 15219157 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15219121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7609610 + 7609611.

It is an arithmetic number, because the mean of its divisors is an integer number (7609611).

Almost surely, 2^15219221 is an apocalyptic number.

It is an amenable number.

15219221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15219221 is an equidigital number, since it uses as much as digits as its factorization.

15219221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 23.

The square root of 15219221 is about 3901.1820003686. The cubic root of 15219221 is about 247.8168360088.

The spelling of 15219221 in words is "fifteen million, two hundred nineteen thousand, two hundred twenty-one".