12138021 has 12 divisors (see below), whose sum is σ = 20037472. Its totient is φ = 6935976.

The previous prime is 12138001. The next prime is 12138023. The reversal of 12138021 is 12083121.

12138021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12138021 - 2⁵ = 12137989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12137985 and 12138003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12138023) 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, 96271 + ... + 96396.

Almost surely, 2^12138021 is an apocalyptic number.

It is an amenable number.

12138021 is a deficient number, since it is larger than the sum of its proper divisors (7899451).

12138021 is a wasteful number, since it uses less digits than its factorization.

12138021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192680 (or 192677 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 12138021 is about 3483.9662742340. The cubic root of 12138021 is about 229.8172524411.

The spelling of 12138021 in words is "twelve million, one hundred thirty-eight thousand, twenty-one".