1 (number)

A die showing the number 1

1 is the Hindu-Arabic numeral for the number one (the unit). It is the smallest positive integer, and smallest natural number. 1 is the multiplicative identity, i.e. any number multiplied by 1 equals itself, for example: $a \cdot 1=a$ and $1\times a=a$.

In Unicode

The codepoint for this character is U+0031 DIGIT ONE.

Other facts

• 1 is the only positive integer that is neither prime nor composite.

• 1 is a divisor of any integer.

$1|n, \forall n \in \N$

• Not only that, but if you do $1[x>1]1$, it will always equal 1.

• 1 is the only odd practical number.

• 1 can't be used as the base nor the argument of logarithms.

1 < 0 | 2 >
0	1	2	3	4	5	6	7	8	9
10	11	12	13	14	15	16	17	18	19
20	21	22	23	24	25	26	27	28	29
30	31	32	33	34	35	36	37	38	39
40	41	42	43	44	45	46	47	48	49
50	51	52	53	54	55	56	57	58	59
60	61	62	63	64	65	66	67	68	69
70	71	72	73	74	75	76	77	78	79
80	81	82	83	84	85	86	87	88	89
90	91	92	93	94	95	96	97	98	99