21210100121100 has 432 divisors, whose sum is σ = 73410667416576. Its totient is φ = 4683265536000.

The previous prime is 21210100121081. The next prime is 21210100121153. The reversal of 21210100121100 is 112100101212.

21210100121100 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 29205994 + ... + 29923406.

Almost surely, 2^{21210100121100} is an apocalyptic number.

21210100121100 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 21210100121100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36705333708288).

21210100121100 is an abundant number, since it is smaller than the sum of its proper divisors (52200567295476).

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

21210100121100 is a wasteful number, since it uses less digits than its factorization.

21210100121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717506 (or 717482 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21210100121100 its reverse (112100101212), we get a palindrome (21322200222312).

The spelling of 21210100121100 in words is "twenty-one trillion, two hundred ten billion, one hundred million, one hundred twenty-one thousand, one hundred".