21021112212100 has 864 divisors, whose sum is σ = 63720544124160. Its totient is φ = 5853612441600.

The previous prime is 21021112212017. The next prime is 21021112212103. The reversal of 21021112212100 is 121221112012.

It is not an unprimeable number, because it can be changed into a prime (21021112212103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 5350242936 + ... + 5350246864.

Almost surely, 2^{21021112212100} is an apocalyptic number.

21021112212100 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 21021112212100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31860272062080).

21021112212100 is an abundant number, since it is smaller than the sum of its proper divisors (42699431912060).

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

21021112212100 is a wasteful number, since it uses less digits than its factorization.

21021112212100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4141 (or 4123 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21021112212100 its reverse (121221112012), we get a palindrome (21142333324112).

It can be divided in two parts, 21021112 and 212100, that added together give a palindrome (21233212).

The spelling of 21021112212100 in words is "twenty-one trillion, twenty-one billion, one hundred twelve million, two hundred twelve thousand, one hundred".