20021102100 has 180 divisors, whose sum is σ = 67722894624. Its totient is φ = 5106784320.

The previous prime is 20021102039. The next prime is 20021102107. The reversal of 20021102100 is 120112002.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021102107) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 132567 + ... + 240033.

Almost surely, 2^20021102100 is an apocalyptic number.

20021102100 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 20021102100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33861447312).

20021102100 is an abundant number, since it is smaller than the sum of its proper divisors (47701792524).

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

20021102100 is a wasteful number, since it uses less digits than its factorization.

20021102100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107516 (or 107500 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 20021102100 its reverse (120112002), we get a palindrome (20141214102).

The spelling of 20021102100 in words is "twenty billion, twenty-one million, one hundred two thousand, one hundred".