9981900 has 72 divisors (see below), whose sum is σ = 32098640. Its totient is φ = 2661120.

The previous prime is 9981899. The next prime is 9981911. The reversal of 9981900 is 91899.

9981900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×9981900² = 199276655220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 852 + ... + 4548.

Almost surely, 2^9981900 is an apocalyptic number.

9981900 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9981900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16049320).

9981900 is an abundant number, since it is smaller than the sum of its proper divisors (22116740).

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

9981900 is a wasteful number, since it uses less digits than its factorization.

9981900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3720 (or 3707 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

The square root of 9981900 is about 3159.4145027204. The cubic root of 9981900 is about 215.3134062741.

The spelling of 9981900 in words is "nine million, nine hundred eighty-one thousand, nine hundred".