21120010020100 has 72 divisors (see below), whose sum is σ = 46287619043400. Its totient is φ = 8363740416000.

The previous prime is 21120010020071. The next prime is 21120010020101. The reversal of 21120010020100 is 102001002112.

It can be written as a sum of positive squares in 12 ways, for example, as 201442982976 + 20918567037124 = 448824^2 + 4573682^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21120010020101) 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, 150712866 + ... + 150852934.

It is an arithmetic number, because the mean of its divisors is an integer number (642883597825).

Almost surely, 2^{21120010020100} is an apocalyptic number.

21120010020100 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 21120010020100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23143809521700).

21120010020100 is an abundant number, since it is smaller than the sum of its proper divisors (25167609023300).

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

21120010020100 is a wasteful number, since it uses less digits than its factorization.

21120010020100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155113 (or 155106 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21120010020100 its reverse (102001002112), we get a palindrome (21222011022212).

The spelling of 21120010020100 in words is "twenty-one trillion, one hundred twenty billion, ten million, twenty thousand, one hundred".