9989978 has 16 divisors (see below), whose sum is σ = 15883560. Its totient is φ = 4704000.

The previous prime is 9989957. The next prime is 9990017. The reversal of 9989978 is 8799899.

It can be written as a sum of positive squares in 4 ways, for example, as 3523129 + 6466849 = 1877^2 + 2543^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 278 + ... + 4478.

Almost surely, 2^9989978 is an apocalyptic number.

9989978 is a deficient number, since it is larger than the sum of its proper divisors (5893582).

9989978 is a wasteful number, since it uses less digits than its factorization.

9989978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4273.

The product of its digits is 2939328, while the sum is 59.

The square root of 9989978 is about 3160.6926456079. The cubic root of 9989978 is about 215.3714724646.

The spelling of 9989978 in words is "nine million, nine hundred eighty-nine thousand, nine hundred seventy-eight".