2100110100021 has 48 divisors (see below), whose sum is σ = 3126416529600. Its totient is φ = 1357457439744.

The previous prime is 2100110100017. The next prime is 2100110100031. The reversal of 2100110100021 is 1200010110012.

It is a happy number.

It is not a de Polignac number, because 2100110100021 - 2² = 2100110100017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 2100110099976 and 2100110100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100110100031) 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 47 ways as a sum of consecutive naturals, for example, 158888005 + ... + 158901221.

It is an arithmetic number, because the mean of its divisors is an integer number (65133677700).

Almost surely, 2^{2100110100021} is an apocalyptic number.

It is an amenable number.

2100110100021 is a deficient number, since it is larger than the sum of its proper divisors (1026306429579).

2100110100021 is a wasteful number, since it uses less digits than its factorization.

2100110100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14898 (or 14895 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 2100110100021 its reverse (1200010110012), we get a palindrome (3300120210033).

Subtracting from 2100110100021 its reverse (1200010110012), we obtain a palindrome (900099990009).

The spelling of 2100110100021 in words is "two trillion, one hundred billion, one hundred ten million, one hundred thousand, twenty-one".