21102110123 has 2 divisors, whose sum is σ = 21102110124. Its totient is φ = 21102110122.

The previous prime is 21102110039. The next prime is 21102110171. The reversal of 21102110123 is 32101120112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21102110123 - 2²⁰ = 21101061547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21102110098 and 21102110107.

It is not a weakly prime, because it can be changed into another prime (21102115123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551055061 + 10551055062.

It is an arithmetic number, because the mean of its divisors is an integer number (10551055062).

Almost surely, 2^21102110123 is an apocalyptic number.

21102110123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102110123 is an equidigital number, since it uses as much as digits as its factorization.

21102110123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21102110123 its reverse (32101120112), we get a palindrome (53203230235).

The spelling of 21102110123 in words is "twenty-one billion, one hundred two million, one hundred ten thousand, one hundred twenty-three".