20681100 has 108 divisors (see below), whose sum is σ = 70750680. Its totient is φ = 5011200.

The previous prime is 20681083. The next prime is 20681107. The reversal of 20681100 is 118602.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20681107) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8856 + ... + 10944.

Almost surely, 2^20681100 is an apocalyptic number.

20681100 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 20681100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35375340).

20681100 is an abundant number, since it is smaller than the sum of its proper divisors (50069580).

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

20681100 is a wasteful number, since it uses less digits than its factorization.

20681100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120 (or 2110 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 20681100 is about 4547.6477436143. The cubic root of 20681100 is about 274.4887470876.

Adding to 20681100 its reverse (118602), we get a palindrome (20799702).

The spelling of 20681100 in words is "twenty million, six hundred eighty-one thousand, one hundred".