There are many numerology systems which assign numerical value to the letters of an alphabet. Examples include the Abjad numerals in Arabic, the Hebrew numerals, Armenian numerals, and Greek numerals. The practice within Jewish tradition of assigning mystical meaning to words based on their numerical values, and on connections between words of equal value, is known as gematria. For example:

1 = a, j, s,
2 = b, t,
3 = c, l, u,
4 = d, m,
5 = e, n, w,
6 = f, o, x,
7 = g, p, y,
8 = h, q, z,
9 = i, r,
based on Pythagorean Numerology, which is the original numerology and was created by the Greek philosopher and mathematician Pythagoras

k = 11
v = 22
...and are then summed.
Examples:
3,489 → 3 + 4 + 8 + 9 = 24 → 2 + 4 = 6
Hello → 8 + 5 + 3 + 3 + 6 = 25 → 2 + 5 = 7

In South India, mostly Tamil nadu, the numbers assigned to English alphabets is different. The list is shown below:
1 = A, I, J, Q, Y
2 = B, K, R
3 = C, G, L, S
4 = D, M, T
5 = E, H, N, X
6 = U, V, W
7 = O, Z
8 = F, P
There is no assignment for the number 9. Numerologists analyze double-digit numbers from 10 to 99.

Some Chinese assign a different set of meanings to the numbers and certain number combinations are considered luckier than others. In general, even numbers are considered lucky, since it is believed that good luck comes in pairs.