How many number one singles does Katy Perry have on the US Billboard Hot 100?
9
2
2
3
2
3
2
1
3
2
1
3
2
1
3
2
1
3
4
2
1
3
4
2
1
3
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
2
1
3
5
4
2
6
1
3
5
4
2
6
1
3
5
4
2
6
1
7
3
5
4
2
6
1
7
3
5
4
2
6
1
7
0
3
5
4
2
8
6
1
7
3
5
4
2
0
8
6
1
7
3
5
4
8
6
1
7
3
5
4
8
6
1
7
5
4
8
6
1
7
5
4
8
6
7
5
4
8
6
10
7
5
4
8
6
10
7
5
13
4
8
6
10
7
9
5
13
8
6
10
7
9
5
13
8
6
10
7
9
5
13
8
6
10
7
9
13
8
6
10
7
12
9
13
8
6
10
7
12
9
13
8
6
10
7
12
9
13
8
10
7
11
12
9
13
8
10
7
11
12
9
13
8
10
ten
ten