999989990 has 8 divisors (see below), whose sum is σ = 1799982000. Its totient is φ = 399995992.

The previous prime is 999989981. The next prime is 999990011. The reversal of 999989990 is 99989999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49999490 + ... + 49999509.

It is an arithmetic number, because the mean of its divisors is an integer number (224997750).

Almost surely, 2^999989990 is an apocalyptic number.

999989990 is a deficient number, since it is larger than the sum of its proper divisors (799992010).

999989990 is a wasteful number, since it uses less digits than its factorization.

999989990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99999006.

The product of its (nonzero) digits is 38263752, while the sum is 71.

The square root of 999989990 is about 31622.6183292908. The cubic root of 999989990 is about 999.9966633222.

The spelling of 999989990 in words is "nine hundred ninety-nine million, nine hundred eighty-nine thousand, nine hundred ninety".