20010021100 has 72 divisors (see below), whose sum is σ = 44246386800. Its totient is φ = 7852550400.

The previous prime is 20010021089. The next prime is 20010021103. The reversal of 20010021100 is 112001002.

It is not an unprimeable number, because it can be changed into a prime (20010021103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3188766 + ... + 3195034.

It is an arithmetic number, because the mean of its divisors is an integer number (614533150).

Almost surely, 2^20010021100 is an apocalyptic number.

20010021100 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 20010021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22123193400).

20010021100 is an abundant number, since it is smaller than the sum of its proper divisors (24236365700).

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

20010021100 is a wasteful number, since it uses less digits than its factorization.

20010021100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6883 (or 6876 counting only the distinct ones).

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

Adding to 20010021100 its reverse (112001002), we get a palindrome (20122022102).

The spelling of 20010021100 in words is "twenty billion, ten million, twenty-one thousand, one hundred".