20081100 has 144 divisors (see below), whose sum is σ = 66106880. Its totient is φ = 4665600.

The previous prime is 20081077. The next prime is 20081107. The reversal of 20081100 is 118002.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (20081107) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73965 + ... + 74235.

Almost surely, 2^20081100 is an apocalyptic number.

20081100 is a gapful number since it is divisible by the number (20) 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 20081100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33053440).

20081100 is an abundant number, since it is smaller than the sum of its proper divisors (46025780).

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

20081100 is a wasteful number, since it uses less digits than its factorization.

20081100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320 (or 313 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 20081100 is about 4481.1940373075. The cubic root of 20081100 is about 271.8081656300.

Adding to 20081100 its reverse (118002), we get a palindrome (20199102).

The spelling of 20081100 in words is "twenty million, eighty-one thousand, one hundred".