1400000000000000000000km in scientific notation

1 400 000 000 000 000 000 000 km = 1.4 * 10^21 km

Tbh i dont really remember how to this this but the only way i could think of solving it is saying how a spuare/rectangle have all equal sides so if they have all equal sides you can divide that number by 4 so 4/30=7.5 so i would say x = 7.5 tell me if its wrong

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