20031021100 has 72 divisors (see below), whose sum is σ = 44752621760. Its totient is φ = 7777788480.

The previous prime is 20031021083. The next prime is 20031021167. The reversal of 20031021100 is 112013002.

It is a Harshad number since it is a multiple of its sum of digits (10).

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, 686611 + ... + 715189.

Almost surely, 2^20031021100 is an apocalyptic number.

20031021100 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 20031021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22376310880).

20031021100 is an abundant number, since it is smaller than the sum of its proper divisors (24721600660).

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

20031021100 is a wasteful number, since it uses less digits than its factorization.

20031021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28799 (or 28792 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 20031021100 its reverse (112013002), we get a palindrome (20143034102).

The spelling of 20031021100 in words is "twenty billion, thirty-one million, twenty-one thousand, one hundred".