21120122100 has 576 divisors, whose sum is σ = 79594905600. Its totient is φ = 4284403200.

The previous prime is 21120122083. The next prime is 21120122113. The reversal of 21120122100 is 122102112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 53199102 + ... + 53199498.

It is an arithmetic number, because the mean of its divisors is an integer number (138185600).

Almost surely, 2^21120122100 is an apocalyptic number.

21120122100 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 21120122100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39797452800).

21120122100 is an abundant number, since it is smaller than the sum of its proper divisors (58474783500).

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

21120122100 is a wasteful number, since it uses less digits than its factorization.

21120122100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21120122100 its reverse (122102112), we get a palindrome (21242224212).

It can be divided in two parts, 2112012 and 2100, that added together give a palindrome (2114112).

The spelling of 21120122100 in words is "twenty-one billion, one hundred twenty million, one hundred twenty-two thousand, one hundred".