1 day contains $$86400$$ seconds and 1 year includes $$365$$ days.
Explanation:
In one year, there are $$365 \times 86400$$ seconds. It
means, one year includes $$31,536,000$$ seconds.
Divide time $$(1.4$$ billion) by this number to get how many
years:
$$=\dfrac{1,400,000,000}{31,536,000}$$
$$=\dfrac{1,400,000}{31,536}=44.394$$ years.
It is approximately $$44.4$$ years.