2121323123 has 4 divisors (see below), whose sum is σ = 2140096008. Its totient is φ = 2102550240.

The previous prime is 2121323101. The next prime is 2121323147. The reversal of 2121323123 is 3213231212.

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 2121323123 - 2²⁰ = 2120274547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121323095 and 2121323104.

It is not an unprimeable number, because it can be changed into a prime (2121323173) 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, 9386273 + ... + 9386498.

It is an arithmetic number, because the mean of its divisors is an integer number (535024002).

Almost surely, 2^2121323123 is an apocalyptic number.

2121323123 is a deficient number, since it is larger than the sum of its proper divisors (18772885).

2121323123 is a wasteful number, since it uses less digits than its factorization.

2121323123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18772884.

The product of its digits is 432, while the sum is 20.

The square root of 2121323123 is about 46057.8236893581. The cubic root of 2121323123 is about 1284.8988546004.

Adding to 2121323123 its reverse (3213231212), we get a palindrome (5334554335).

The spelling of 2121323123 in words is "two billion, one hundred twenty-one million, three hundred twenty-three thousand, one hundred twenty-three".