20001021100 has 18 divisors (see below), whose sum is σ = 43402216004. Its totient is φ = 8000408400.

The previous prime is 20001021097. The next prime is 20001021119. The reversal of 20001021100 is 112010002.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 100005006 + ... + 100005205.

Almost surely, 2^20001021100 is an apocalyptic number.

20001021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20001021100 is an abundant number, since it is smaller than the sum of its proper divisors (23401194904).

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

20001021100 is a wasteful number, since it uses less digits than its factorization.

20001021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200010225 (or 200010218 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 20001021100 its reverse (112010002), we get a palindrome (20113031102).

The spelling of 20001021100 in words is "twenty billion, one million, twenty-one thousand, one hundred".