Aside from the fact that the characters are a perfect match for the Katakana [Japanese] /heroo/ and fit perfectly with the style, there is just no match for the Arabic numerals.
The leftmost character could be the 'eastern Arabic' numeral for 8, not 6, but both 'legs' of the figure are normally the same length. If it were Arabic, which it is not, there would have to be a rational explanation why the form has been modified to conform exactly to the Katakana /he/
In theory, the second character could be the 'eastern Arabic' numeral for 5, but only if you hammer on it to make it look like the Katakana symbol for 'ro'. Normally it is an elongated circle (or the way the Iranians do it, an upside-down 'hearts' shape).
The third character is NOT a numeral, but could be a dash. A zero in the 'eastern Arabic' numerals is ALWAYS a dot, usually stylized to look like a lozenge shape.
For anyone who is curious, the 'western Arabic' numerals are those currently used in Europe: 1234567890
Although both Arabic and Hebrew are written from right to left, the numerals are written from left to right, regardless whether they are of the western or the eastern form.
But the ring is Japanese, guys. Hellooooo ...