What is the meaning of Quintillion?

Either of two very large amounts:

  1. A billion billion: 1 followed by eighteen zeros, 10.

    A billion billion: 1 followed by eighteen zeros, 10.

    A million quadrillion: 1 followed by 30 zeros, 10.

    An unspecified very large number.

    Any very large number, exceeding normal description.

    nonillion (10)

    quintillion (10)

    Source: wiktionary.org