9909888 has 64 divisors (see below), whose sum is σ = 26658720. Its totient is φ = 3261440.

The previous prime is 9909881. The next prime is 9909901. The reversal of 9909888 is 8889099.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 9909888.

It is not an unprimeable number, because it can be changed into a prime (9909881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50206 + ... + 50402.

Almost surely, 2^9909888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9909888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13329360).

9909888 is an abundant number, since it is smaller than the sum of its proper divisors (16748832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9909888 is a wasteful number, since it uses less digits than its factorization.

9909888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 51.

The square root of 9909888 is about 3147.9974587029. The cubic root of 9909888 is about 214.7943806637.

It can be divided in two parts, 990 and 9888, that added together give a triangular number (10878 = T₁₄₇).

The spelling of 9909888 in words is "nine million, nine hundred nine thousand, eight hundred eighty-eight".