Definition of

Peta-

A prefix meaning one-quadrillion (1,000,000,000,000,000 or 1015)

The same as multiplying by 1015

Examples:
• there are about a quadrillion ants on Earth (10 times more or less, no one knows exactly)
• 1 light year (how far light travels in a vacuum in one year) is about 9.461 quadrillion meters

Symbol is P

Example: 12 Pm = 12 petameters = 12 quadrillion meters (12,000,000,000,000,000 m)

Peta-