9999988 has 6 divisors (see below), whose sum is σ = 17499986.
Its totient is φ = 4999992.
The previous prime is 9999973. The next prime is 9999991. The reversal of 9999988 is 8899999.
It can be written as a sum of positive squares in only one way, i.e., 9498724 + 501264 = 3082^2 + 708^2
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is a congruent number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1249995 + ... + 1250002.
Almost surely, 29999988 is an apocalyptic number.
It is an amenable number.
9999988 is a deficient number, since it is larger than the sum of its proper divisors (7499998).
9999988 is a wasteful number, since it uses less digits than its factorization.
9999988 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2500001 (or 2499999 counting only the distinct ones).
The product of its digits is 3779136, while the sum is 61.
The square root of 9999988 is about 3162.2757628012.
The cubic root of 9999988 is about 215.4433828258.
The spelling of 9999988 in words is "nine million, nine hundred ninety-nine thousand, nine hundred eighty-eight".