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130 (one hundred thirty) is the natural number following 129 and preceding 131.

In mathematics

130 is a sphenic number. It is a noncototient since there is no answer to the equation x - φ(x) = 130.

130 is the only integer that is the sum of the squares of its first four divisors, including 1: 1 + 2 + 5 + 10 = 130.

130 is the largest number that cannot be written as the sum of four hexagonal numbers.

130 equals both 2 + 2 and 5 + 5 and is therefore a doubly strictly adsurd number.

In other fields

• A 130-30 fund or a ratio up to 150/50 is a type of collective investment vehicle

References

1. MathWorld - Hexagonal Number
2. Mackenzie, Dana (March 2018). "2184: An Absurd (and Adsurd) Tale". Integers. 18.

• Integers