def factorization(n):
    arr = []
    temp = n
    i=2
    while i*i<=n:
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr.append([i, cnt])
        i+=1
    if temp!=1:
        arr.append([temp, 1])
    return arr


def cmb(n, r, p):
    if (r < 0) or (n < r):
        return 0
    r = min(r, n - r)
    return fact[n] * factinv[r] * factinv[n-r] % p

p=998244353
N = 2*10**6  # N は必要分だけ用意する
fact = [1, 1]  # fact[n] = (n! mod p)
factinv = [1, 1]  # factinv[n] = ((n!)^(-1) mod p)
inv = [0, 1]  # factinv 計算用S
 
for i in range(2, N + 1):
    fact.append((fact[-1] * i) % p)
    inv.append((-inv[p % i] * (p // i)) % p)
    factinv.append((factinv[-1] * inv[-1]) % p)

Q=int(input())
count=0
for _ in range(Q):
    a,b=map(int,input().split())
    for c,d in factorization(a):
        count+=d
    if count<b:
        print(0)
    else:
        print(cmb(count-1,b-1,p))