20121220002100 has 54 divisors (see below), whose sum is σ = 50791708217670. Its totient is φ = 6898703999040.

The previous prime is 20121220002067. The next prime is 20121220002113. The reversal of 20121220002100 is 120002212102.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 16434727204 + 20104785274896 = 128198^2 + 4483836^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2053180815 + ... + 2053190614.

Almost surely, 2^{20121220002100} is an apocalyptic number.

20121220002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121220002100 is an abundant number, since it is smaller than the sum of its proper divisors (30670488215570).

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

20121220002100 is a wasteful number, since it uses less digits than its factorization.

20121220002100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4106371457 (or 4106371443 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20121220002100 its reverse (120002212102), we get a palindrome (20241222214202).

The spelling of 20121220002100 in words is "twenty trillion, one hundred twenty-one billion, two hundred twenty million, two thousand, one hundred".