9918878689 has 8 divisors (see below), whose sum is σ = 9999623168. Its totient is φ = 9838175760.

The previous prime is 9918878659. The next prime is 9918878741. The reversal of 9918878689 is 9868788199.

9918878689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 9918878689 - 2⁷ = 9918878561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9918878659) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 625519 + ... + 641179.

It is an arithmetic number, because the mean of its divisors is an integer number (1249952896).

Almost surely, 2^9918878689 is an apocalyptic number.

It is an amenable number.

9918878689 is a deficient number, since it is larger than the sum of its proper divisors (80744479).

9918878689 is a wasteful number, since it uses less digits than its factorization.

9918878689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20775.

The product of its digits is 125411328, while the sum is 73.

The square root of 9918878689 is about 99593.5675081478. The cubic root of 9918878689 is about 2148.5931801924.

The spelling of 9918878689 in words is "nine billion, nine hundred eighteen million, eight hundred seventy-eight thousand, six hundred eighty-nine".