535

535 = 5 x 107

5, 3, and 5 are the eighth, ninth, and tenth decimal digits of pi.

535 is a number that cannot be written as a sum of three squares.

535⁵³⁵ + (535 - 1) is a prime number.

535 is the smallest palindrome such that its cube can be written as a sum of three prime cubes: 535³ = 349³ + 379³ + 383³.

The Indonesian volcano Krakatoa erupted in the year 535.

Source: Prime Curios!