21002100020103 has 16 divisors (see below), whose sum is σ = 28056986636000. Its totient is φ = 13974311185920.

The previous prime is 21002100020089. The next prime is 21002100020147. The reversal of 21002100020103 is 30102000120012.

It is not a de Polignac number, because 21002100020103 - 2⁵ = 21002100020071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002100021103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18417723 + ... + 19524771.

It is an arithmetic number, because the mean of its divisors is an integer number (1753561664750).

Almost surely, 2^{21002100020103} is an apocalyptic number.

21002100020103 is a deficient number, since it is larger than the sum of its proper divisors (7054886615897).

21002100020103 is a wasteful number, since it uses less digits than its factorization.

21002100020103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119282.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21002100020103 its reverse (30102000120012), we get a palindrome (51104100140115).

Subtracting 21002100020103 from its reverse (30102000120012), we obtain a palindrome (9099900099909).

The spelling of 21002100020103 in words is "twenty-one trillion, two billion, one hundred million, twenty thousand, one hundred three".