21123321123223 has 4 divisors (see below), whose sum is σ = 23043623043528. Its totient is φ = 19203019202920.

The previous prime is 21123321123217. The next prime is 21123321123241. The reversal of 21123321123223 is 32232112332112.

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 21123321123223 - 2¹³ = 21123321115031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123321123191 and 21123321123200.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 960150960136 + ... + 960150960157.

It is an arithmetic number, because the mean of its divisors is an integer number (5760905760882).

Almost surely, 2^{21123321123223} is an apocalyptic number.

21123321123223 is a deficient number, since it is larger than the sum of its proper divisors (1920301920305).

21123321123223 is a wasteful number, since it uses less digits than its factorization.

21123321123223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920301920304.

The product of its digits is 5184, while the sum is 28.

Adding to 21123321123223 its reverse (32232112332112), we get a palindrome (53355433455335).

The spelling of 21123321123223 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred twenty-one million, one hundred twenty-three thousand, two hundred twenty-three".