21012222022100 has 72 divisors (see below), whose sum is σ = 46369963778208. Its totient is φ = 8262473212800.

The previous prime is 21012222022079. The next prime is 21012222022109. The reversal of 21012222022100 is 122022221012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012222022109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9936899 + ... + 11864501.

Almost surely, 2^{21012222022100} is an apocalyptic number.

21012222022100 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 21012222022100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23184981889104).

21012222022100 is an abundant number, since it is smaller than the sum of its proper divisors (25357741756108).

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

21012222022100 is a wasteful number, since it uses less digits than its factorization.

21012222022100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1929465 (or 1929458 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21012222022100 its reverse (122022221012), we get a palindrome (21134244243112).

The spelling of 21012222022100 in words is "twenty-one trillion, twelve billion, two hundred twenty-two million, twenty-two thousand, one hundred".