20121111002100 has 144 divisors (see below), whose sum is σ = 59170059748800. Its totient is φ = 5278409579520.

The previous prime is 20121111002081. The next prime is 20121111002117. The reversal of 20121111002100 is 120011112102.

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 47 ways as a sum of consecutive naturals, for example, 3347211 + ... + 7172589.

It is an arithmetic number, because the mean of its divisors is an integer number (410903192700).

Almost surely, 2^{20121111002100} is an apocalyptic number.

20121111002100 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 20121111002100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29585029874400).

20121111002100 is an abundant number, since it is smaller than the sum of its proper divisors (39048948746700).

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

20121111002100 is a wasteful number, since it uses less digits than its factorization.

20121111002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3825682 (or 3825675 counting only the distinct ones).

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

Adding to 20121111002100 its reverse (120011112102), we get a palindrome (20241122114202).

The spelling of 20121111002100 in words is "twenty trillion, one hundred twenty-one billion, one hundred eleven million, two thousand, one hundred".