15450221 has 2 divisors, whose sum is σ = 15450222. Its totient is φ = 15450220.

The previous prime is 15450217. The next prime is 15450233. The reversal of 15450221 is 12205451.

15450221 is nontrivially palindromic in base 12.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14478025 + 972196 = 3805^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 15450221 - 2² = 15450217 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 15450193 and 15450202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15450241) 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, 7725110 + 7725111.

It is an arithmetic number, because the mean of its divisors is an integer number (7725111).

Almost surely, 2^15450221 is an apocalyptic number.

It is an amenable number.

15450221 is a deficient number, since it is larger than the sum of its proper divisors (1).

15450221 is an equidigital number, since it uses as much as digits as its factorization.

15450221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 15450221 is about 3930.6769137135. The cubic root of 15450221 is about 249.0643479227.

Adding to 15450221 its reverse (12205451), we get a palindrome (27655672).

The spelling of 15450221 in words is "fifteen million, four hundred fifty thousand, two hundred twenty-one".