The spooks seem to use 2 numerology encryptions: One is that any given number can be written in Hebrew letters, which will then spell out a word. Usually that’s not the exact spelling, but again a pun with a similar word, e.g. aces & eights, which spells chay but puns with chawy. The other method is that a number is pronounced like some other word, or has a meaning besides its numerical value, like number 2. The former is usually used with multi-digit numbers, the latter with single-digits.