That's a way to ensure accurate understanding of component values. A decimal point is very important, but it can be overlooked or omitted, so the value is written with the multiplier positioned where the decimal point would be.

The letter "k" means 1000, so "1k7" would be 1.7 x 1000 = 1700 Ohms, or 1.7 k Ohms.

The letter "M" means 1,000,000, so "5M6" would mean 5.6 Meg, or 5,600,000 Ohms.