OK I typed in Tom Marvolo Riddle on the Sorcerors Companion thing and this is what it came up with-

Character Number: 7
Heart Number : 6
Social Number: 1

I find this quite interesting-
No 7.
Perceptive, understanding, and bright, sevens enjoy hard work and challenges. They are often serious, scholarly, and interested in all things mysterious. Originality and imagination are more important than money and material possessions. Sevens can also be pessimistic, sarcastic, and insecure.

To a degree, that suits Voldemort, as he was when at Hogwarts. He was scholarly and interested in things mysterious, like horcrux's but can he really be called 'understanding'?!

Inidentally, my heart number was 7.

No*6
Six represents harmony, friendship, and family life. Sixes are loyal, reliable, and loving. They adapt easily. They do well in teaching and the arts, but are often unsuccessful in business. They are sometimes prone to gossip and complacency.

Sound like Voldy? Noooooo way! Though he did want to teach.

No 1
This is the number of the individual, the solitary unit. Ones are independent, focused, and determined. They set a goal and stick to it. They are leaders and inventors. Ones find it difficult to work with others and don't like to take orders. They can be self-centered, egotistical, and domineering. They are often loners.*

That sounds more like him.