21121001110123 has 2 divisors, whose sum is σ = 21121001110124. Its totient is φ = 21121001110122.

The previous prime is 21121001110081. The next prime is 21121001110141. The reversal of 21121001110123 is 32101110012112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121001110123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21121001110097 and 21121001110106.

It is not a weakly prime, because it can be changed into another prime (21121001111123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560500555061 + 10560500555062.

It is an arithmetic number, because the mean of its divisors is an integer number (10560500555062).

Almost surely, 2^{21121001110123} is an apocalyptic number.

21121001110123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121001110123 is an equidigital number, since it uses as much as digits as its factorization.

21121001110123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21121001110123 its reverse (32101110012112), we get a palindrome (53222111122235).

It can be divided in two parts, 2112100 and 1110123, that added together give a palindrome (3222223).

The spelling of 21121001110123 in words is "twenty-one trillion, one hundred twenty-one billion, one million, one hundred ten thousand, one hundred twenty-three".