21102122002100 has 72 divisors (see below), whose sum is σ = 46088754844440. Its totient is φ = 8386188410880.

The previous prime is 21102122002057. The next prime is 21102122002139. The reversal of 21102122002100 is 120022120112.

It can be written as a sum of positive squares in 12 ways, for example, as 7201483539364 + 13900638462736 = 2683558^2 + 3728356^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14130794 + ... + 15552606.

Almost surely, 2^{21102122002100} is an apocalyptic number.

21102122002100 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 21102122002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23044377422220).

21102122002100 is an abundant number, since it is smaller than the sum of its proper divisors (24986632842340).

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

21102122002100 is a wasteful number, since it uses less digits than its factorization.

21102122002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1422789 (or 1422782 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21102122002100 its reverse (120022120112), we get a palindrome (21222144122212).

The spelling of 21102122002100 in words is "twenty-one trillion, one hundred two billion, one hundred twenty-two million, two thousand, one hundred".