Although the decimal point doesn't show in this number, it is actually positioned after the number itself, because the number is a whole number. So the decimal point comes after the 907.
Next we count how many digits there are between this position and the first digit of the number (1). There are 7 digits. Remember that.
Next, we place the decimal point immediately after the first digit: 1.2674907. To get the decimal point from where it was at the end, we had to move it 7 places to the left. This tells us the exponent of 10 that's needed to write the number in standard form, in other words we multiply by 10^7 which can also be written E7 (E stands for exponent).
The number in standard form is therefore 1.2674907 x 10^7 or 1.2674907E7. If you were handwriting the exponent of 10 it would be a superscript 7 on 10, but because we don't usually have superscript formats on a computer it's represented by 10^7.