12123023021 has 4 divisors (see below), whose sum is σ = 12123287232. Its totient is φ = 12122758812.

The previous prime is 12123023009. The next prime is 12123023023. The reversal of 12123023021 is 12032032121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12032032121 = 44699 ⋅269179.

It is a cyclic number.

It is not a de Polignac number, because 12123023021 - 2²² = 12118828717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12123023023) 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, 43445 + ... + 161658.

It is an arithmetic number, because the mean of its divisors is an integer number (3030821808).

Almost surely, 2^12123023021 is an apocalyptic number.

It is an amenable number.

12123023021 is a deficient number, since it is larger than the sum of its proper divisors (264211).

12123023021 is an equidigital number, since it uses as much as digits as its factorization.

12123023021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264210.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 12123023021 its reverse (12032032121), we get a palindrome (24155055142).

The spelling of 12123023021 in words is "twelve billion, one hundred twenty-three million, twenty-three thousand, twenty-one".