21123321123203 has 16 divisors (see below), whose sum is σ = 23287013852256. Its totient is φ = 19036984538880.

The previous prime is 21123321123187. The next prime is 21123321123217. The reversal of 21123321123203 is 30232112332112.

It is a cyclic number.

It is not a de Polignac number, because 21123321123203 - 2⁴ = 21123321123187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123321123293) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6619868 + ... + 9277353.

It is an arithmetic number, because the mean of its divisors is an integer number (1455438365766).

Almost surely, 2^{21123321123203} is an apocalyptic number.

21123321123203 is a deficient number, since it is larger than the sum of its proper divisors (2163692729053).

21123321123203 is a wasteful number, since it uses less digits than its factorization.

21123321123203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15899654.

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 21123321123203 its reverse (30232112332112), we get a palindrome (51355433455315).

The spelling of 21123321123203 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred twenty-one million, one hundred twenty-three thousand, two hundred three".