12

12 = 2 × 2 × 3

12 = 3 × 4 (See also 56 = 7 × 8)

12 = 123 + 45 − 67 − 89

12 = 987 − 654 − 321

12 = −0^0 + 1^8 − 2^7 − 3^9 + 4^5 + 5^6 + 6^2 + 7^4 + 8^1 + 9^3

12 = 2^2 + 2^2 + 2^2

12⁵= 4⁵+ 5⁵+ 6⁵+ 7⁵+ 9⁵+ 11⁵

\( 12 = 3^2 + 1^2 + 1^2 + 1^2 = 2^2 + 2^2 + 2^2 \)

12 = 11 + 1
= 2 × (2 + 2 + 2)
= 3 + 3 × 3
= 4 + 4 + 4 = 4 ×(4 − 4 ÷ 4) = (44 + 4) ÷ 4
= 6 + 6
= (55 + 5)/5
= (77 + 7)/7
= (88 + 8)/8
= (99 + 9)/9

\( 12^8 \approx 11^8 + 11^8 \) Fermat approximate solutions

Abundant number : 12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66, 70, 72, 78, 80, 84, 88, 90, 96, 100, 102, 104, 108, 112, 114, 120, ... (sequence A005101 in the OEIS).

Number k such that k! - 1 is Prime

Number k such that 9^k + 2 is prime.

Positive integer n such that n^11 + 1 is semiprime.

Number of Integer partitions of 12: 77

Number of vertices in a hexagon when n internal hexagons are drawn between the 6n points that divide each side into n+1 equal parts (n= 1 )

Numbers of edges of regular polygon constructible with unmarked straightedge and compass.

Number that is the sum of 12 positive 10th powers.

Number of ways to partition 2n+1 into distinct positive integers, n = 7

Factors: 1, 2, 3, 4, 6, 12

Twelve

Representations, Binary to Hexadecimal:

1100_2
110_3
30_4
22_5
20_6
15_7
14_8
13_9
11_11
10_12
c_13
c_14
c_15
c_16

11 <--- ---> 13