15798221 has 2 divisors, whose sum is σ = 15798222. Its totient is φ = 15798220.

The previous prime is 15798199. The next prime is 15798227. The reversal of 15798221 is 12289751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15100996 + 697225 = 3886^2 + 835^2 .

It is a cyclic number.

It is not a de Polignac number, because 15798221 - 2¹⁸ = 15536077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15798227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7899110 + 7899111.

It is an arithmetic number, because the mean of its divisors is an integer number (7899111).

Almost surely, 2^15798221 is an apocalyptic number.

It is an amenable number.

15798221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15798221 is an equidigital number, since it uses as much as digits as its factorization.

15798221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 35.

The square root of 15798221 is about 3974.6975985602. The cubic root of 15798221 is about 250.9204522449.

The spelling of 15798221 in words is "fifteen million, seven hundred ninety-eight thousand, two hundred twenty-one".