21110123 has 2 divisors, whose sum is σ = 21110124. Its totient is φ = 21110122.

The previous prime is 21110099. The next prime is 21110129. The reversal of 21110123 is 32101112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21110123 - 2⁸ = 21109867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21110129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555061 + 10555062.

It is an arithmetic number, because the mean of its divisors is an integer number (10555062).

Almost surely, 2^21110123 is an apocalyptic number.

21110123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110123 is an equidigital number, since it uses as much as digits as its factorization.

21110123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21110123 is about 4594.5753884336. The cubic root of 21110123 is about 276.3738326771.

Adding to 21110123 its reverse (32101112), we get a palindrome (53211235).

The spelling of 21110123 in words is "twenty-one million, one hundred ten thousand, one hundred twenty-three".