n=int(input())
M=998244353
fa=[1,1]
fb=[1,1]
for i in range(2,3*10**6+1):
  fa+=[fa[-1]*i%M]
  fb+=[fb[-1]*(M//i)*fb[M%i]*fa[M%i-1]*(-1)%M]
fc=lambda n,k:fa[n]*fb[k]*fb[n-k]%M if n>=k else 0
f=lambda b,c:fc(c-b+b-1,b-1)
c=0
for _ in range(n):
  a,b=map(int,input().split())
  i=2
  while i*i<=a:
    if a%i==0:
      while a%i==0:
        a//=i
        c+=1
    i+=1
  c+=a>1
  print(f(b,c))