21101101010123 has 4 divisors (see below), whose sum is σ = 21101125952088. Its totient is φ = 21101076068160.

The previous prime is 21101101010111. The next prime is 21101101010149. The reversal of 21101101010123 is 32101010110112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21101101010123 - 2¹⁰ = 21101101009099 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101101010098 and 21101101010107.

It is not an unprimeable number, because it can be changed into a prime (21101101010023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11155733 + ... + 12909398.

It is an arithmetic number, because the mean of its divisors is an integer number (5275281488022).

Almost surely, 2^{21101101010123} is an apocalyptic number.

21101101010123 is a deficient number, since it is larger than the sum of its proper divisors (24941965).

21101101010123 is an equidigital number, since it uses as much as digits as its factorization.

21101101010123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24941964.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21101101010123 its reverse (32101010110112), we get a palindrome (53202111120235).

The spelling of 21101101010123 in words is "twenty-one trillion, one hundred one billion, one hundred one million, ten thousand, one hundred twenty-three".