9981800 has 48 divisors (see below), whose sum is σ = 24021900. Its totient is φ = 3852800.

The previous prime is 9981799. The next prime is 9981809. The reversal of 9981800 is 81899.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 4937284 + 5044516 = 2222^2 + 2246^2 .

It is not an unprimeable number, because it can be changed into a prime (9981809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4940 + ... + 6660.

Almost surely, 2^9981800 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 9981800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12010950).

9981800 is an abundant number, since it is smaller than the sum of its proper divisors (14040100).

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

9981800 is a wasteful number, since it uses less digits than its factorization.

9981800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1766 (or 1757 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 35.

The square root of 9981800 is about 3159.3986769637. The cubic root of 9981800 is about 215.3126872590.

The spelling of 9981800 in words is "nine million, nine hundred eighty-one thousand, eight hundred".