248 (number) explained

248 (two hundred [and] forty-eight) is the natural number following 247 and preceding 249.

Additionally, 248 is:

• a nontotient.
• a refactorable number.
• an untouchable number.^[1]
• palindromic in bases 13 (161₁₃), 30 (88₃₀), 61 (44₆₁) and 123 (22₁₂₃).
• a Harshad number in bases 3, 4, 6, 7, 9, 11, 13 (and 18 other bases).
• part of the 43-aliquot tree. The aliquot sequence starting at 248 is: 248, 232, 218, 112, 136, 134, 70, 74, 40, 50, 43, 1, 0.

The exceptional Lie group E₈ has dimension 248.

Notes and References

1. Untouchable numbers: impossible values for sum of aliquot parts of n.