9991438558 has 8 divisors (see below), whose sum is σ = 15069960360. Its totient is φ = 4968118440.

The previous prime is 9991438549. The next prime is 9991438559. The reversal of 9991438558 is 8558341999.

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

It is a junction number, because it is equal to n+sod(n) for n = 9991438496 and 9991438505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991438559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13799968 + ... + 13800691.

It is an arithmetic number, because the mean of its divisors is an integer number (1883745045).

Almost surely, 2^9991438558 is an apocalyptic number.

9991438558 is a deficient number, since it is larger than the sum of its proper divisors (5078521802).

9991438558 is a wasteful number, since it uses less digits than its factorization.

9991438558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27600842.

The product of its digits is 13996800, while the sum is 61.

The square root of 9991438558 is about 99957.1836237896. The cubic root of 9991438558 is about 2153.8196788977.

The spelling of 9991438558 in words is "nine billion, nine hundred ninety-one million, four hundred thirty-eight thousand, five hundred fifty-eight".