the number 137 appears in various situations.
in mathematics, 137 is a prime number.
in the periodic table, Cs 137 can be found.
in physics, we have the fine-structure constant,
the formula converting becquerel into Sv is
x[mSv/year] = m[kg] × a[Bq] × 1/137.
where x is the annual radiation dose,m is the mass of radioactive material,
a is the activity of a quantity of the mass.
the age of our universe is around 13.7 billion.