Evil Number Calculator

The Evil Number Calculator is a free online tool used to check if the number is an evil number.

Evil Number Calculator

Eg, Is 17 an evil number? Enter 17 into the input box and click Calculate button.

What is an evil number?

An evil number is a non-negative integer that has an even number of 1s in its binary expansion. Therefore, to judge whether a positive integer is an evil number or not, two steps must be taken:

Convert decimal integer to binary.
Count the number of 1s in binary. If the number of 1s is even, it is an evil number. If the number of 1s is odd, it is an odious number.

For example, Is 17 an evil number?

First, Convert 17 to binary.

17 = 10001

Obviously, there are two 1s in binary. So, 17 is an evil number.

First 100 evil numbers

0	3	5	6	9	10	12	15	17	18
20	23	24	27	29	30	33	34	36	39
40	43	45	46	48	51	53	54	57	58
60	63	65	66	68	71	72	75	77	78
80	83	85	86	89	90	92	95	96	99
101	102	105	106	108	111	113	114	116	119
120	123	125	126	129	130	132	135	136	139
141	142	144	147	149	150	153	154	156	159
160	163	165	166	169	170	172	175	177	178
180	183	184	187	189	190	192	195	197	198

How to use the evil number calculator

The procedure to use the evil number calculator is as follows:

1Enter the positive number.
2Click Calculate button to verify whether the input number is an evil number.
3Click the Reset button to start a new verification.

Solved examples using the evil number calculator

Example 1: Is 1666 an evil number?

Enter 1666 into the input box and click Calculate button, as shown in the figure, 1666 is an evil number.

1666 = 11010000010

The number of 1s is even. So, 1666 is an evil number.

Example 2: Is 2024 an evil number?

Enter 2024 into the input box and click Calculate button, as shown in the figure, 2024 is not an evil number, it is an odious number.

2024 = 11111101000

There are 7 1s in binary. So, 2024 is an odious number.

Evil Number Calculator