Given: 8.6e12 * This is also a scientific notation, and usually called E-notation.
In the given equation, "8.6" is called significand that adds preciseness to the number. Significand is a real number.
"e" means (8.6) times 10 raised to the power of (12). Notice that "e" is not the base of natural logarithm (≈2.71828...). Upper case "E" is also used instead of lower case "e" to avoid confusion.
"12" is the exponent. Exponent is an integer. Thus, 8.6e12 is equivalent to 8.6x10^12.
Therefore, the answer is: 8.6e12=8.6x10^12 (: eight trillion, six hundred billion)
* This kind of shortest expressions of numbers are widely used to program softwares for computers or calculators, or carry on programmed instructions.