21010113323123 has 4 divisors (see below), whose sum is σ = 21042788461128. Its totient is φ = 20977438185120.

The previous prime is 21010113322973. The next prime is 21010113323203. The reversal of 21010113323123 is 32132331101012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010113323123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010113323623) 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, 16337568038 + ... + 16337569323.

It is an arithmetic number, because the mean of its divisors is an integer number (5260697115282).

Almost surely, 2^{21010113323123} is an apocalyptic number.

21010113323123 is a deficient number, since it is larger than the sum of its proper divisors (32675138005).

21010113323123 is an equidigital number, since it uses as much as digits as its factorization.

21010113323123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32675138004.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 21010113323123 its reverse (32132331101012), we get a palindrome (53142444424135).

The spelling of 21010113323123 in words is "twenty-one trillion, ten billion, one hundred thirteen million, three hundred twenty-three thousand, one hundred twenty-three".