M=998244353
n=int(input())
g=n*(n+1)//2
g%=M
for i in range(2,n+1):
  g+=(((n-i+1)//i)*((n-i+1)//i+1)//2)*i
  g+=((n-i+1)//i+1)*((n-i+1)%i)
  g%=M
print(g)