Pandas convert string to int

You need add parameter errors="coerce" to function to_numeric:

ID = pd.to_numeric(ID, errors="coerce")

If ID is column:

df.ID = pd.to_numeric(df.ID, errors="coerce")

but non numeric are converted to NaN, so all values are float.

For int need convert NaN to some value e.g. 0 and then cast to int:

df.ID = pd.to_numeric(df.ID, errors="coerce").fillna(0).astype(np.int64)

Sample:

df = pd.DataFrame({'ID':['4806105017087','4806105017087','CN414149']})
print (df)
              ID
0  4806105017087
1  4806105017087
2       CN414149

print (pd.to_numeric(df.ID, errors="coerce"))
0    4.806105e+12
1    4.806105e+12
2             NaN
Name: ID, dtype: float64

df.ID = pd.to_numeric(df.ID, errors="coerce").fillna(0).astype(np.int64)
print (df)
              ID
0  4806105017087
1  4806105017087
2              0

EDIT: If use pandas 0.25+ then is possible use integer_na:

df.ID = pd.to_numeric(df.ID, errors="coerce").astype('Int64')
print (df)
              ID
0  4806105017087
1  4806105017087
2            NaN