9999888444 has 432 divisors, whose sum is σ = 33974767008. Its totient is φ = 2449391616.

The previous prime is 9999888439. The next prime is 9999888463. The reversal of 9999888444 is 4448889999.

9999888444 is a `hidden beast` number, since 9 + 99 + 98 + 8 + 8 + 444 = 666.

It is a super-2 number, since 2×9999888444² (a number of 21 digits) contains 22 as substring.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 44052259 + ... + 44052485.

It is an arithmetic number, because the mean of its divisors is an integer number (78645294).

Almost surely, 2^9999888444 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 9999888444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16987383504).

9999888444 is an abundant number, since it is smaller than the sum of its proper divisors (23974878564).

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

9999888444 is a wasteful number, since it uses less digits than its factorization.

9999888444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394 (or 382 counting only the distinct ones).

The product of its digits is 214990848, while the sum is 72.

The square root of 9999888444 is about 99999.4422184444. The cubic root of 9999888444 is about 2154.4266786649.

The spelling of 9999888444 in words is "nine billion, nine hundred ninety-nine million, eight hundred eighty-eight thousand, four hundred forty-four".