2100121110021 has 32 divisors (see below), whose sum is σ = 3090885710976. Its totient is φ = 1257772032000.

The previous prime is 2100121110013. The next prime is 2100121110049. The reversal of 2100121110021 is 1200111210012.

It is not a de Polignac number, because 2100121110021 - 2³ = 2100121110013 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2100121109979 and 2100121110006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100121110221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1619581 + ... + 2612141.

It is an arithmetic number, because the mean of its divisors is an integer number (96590178468).

Almost surely, 2^{2100121110021} is an apocalyptic number.

It is an amenable number.

2100121110021 is a deficient number, since it is larger than the sum of its proper divisors (990764600955).

2100121110021 is a wasteful number, since it uses less digits than its factorization.

2100121110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 993333.

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

Adding to 2100121110021 its reverse (1200111210012), we get a palindrome (3300232320033).

Subtracting from 2100121110021 its reverse (1200111210012), we obtain a palindrome (900009900009).

The spelling of 2100121110021 in words is "two trillion, one hundred billion, one hundred twenty-one million, one hundred ten thousand, twenty-one".