20210221100 has 72 divisors (see below), whose sum is σ = 44801820000. Its totient is φ = 7911129600.

The previous prime is 20210221079. The next prime is 20210221123. The reversal of 20210221100 is 112201202.

It is a happy number.

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, 1205576 + ... + 1222224.

It is an arithmetic number, because the mean of its divisors is an integer number (622247500).

Almost surely, 2^20210221100 is an apocalyptic number.

20210221100 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 20210221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22400910000).

20210221100 is an abundant number, since it is smaller than the sum of its proper divisors (24591598900).

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

20210221100 is a wasteful number, since it uses less digits than its factorization.

20210221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16923 (or 16916 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20210221100 its reverse (112201202), we get a palindrome (20322422302).

The spelling of 20210221100 in words is "twenty billion, two hundred ten million, two hundred twenty-one thousand, one hundred".