12123200021 has 12 divisors (see below), whose sum is σ = 13556088480. Its totient is φ = 10809535680.

The previous prime is 12123200017. The next prime is 12123200027. The reversal of 12123200021 is 12000232121.

It is a happy number.

It is not a de Polignac number, because 12123200021 - 2² = 12123200017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12123199969 and 12123200005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12123200027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1098425 + ... + 1109406.

It is an arithmetic number, because the mean of its divisors is an integer number (1129674040).

Almost surely, 2^12123200021 is an apocalyptic number.

It is an amenable number.

12123200021 is a deficient number, since it is larger than the sum of its proper divisors (1432888459).

12123200021 is a wasteful number, since it uses less digits than its factorization.

12123200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2207884 (or 2207867 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 12123200021 its reverse (12000232121), we get a palindrome (24123432142).

The spelling of 12123200021 in words is "twelve billion, one hundred twenty-three million, two hundred thousand, twenty-one".