12166021 has 4 divisors (see below), whose sum is σ = 13904032. Its totient is φ = 10428012.

The previous prime is 12166019. The next prime is 12166027. The reversal of 12166021 is 12066121.

12166021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is not a de Polignac number, because 12166021 - 2¹ = 12166019 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12166021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12166027) 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, 868995 + ... + 869008.

It is an arithmetic number, because the mean of its divisors is an integer number (3476008).

Almost surely, 2^12166021 is an apocalyptic number.

It is an amenable number.

12166021 is a deficient number, since it is larger than the sum of its proper divisors (1738011).

12166021 is an equidigital number, since it uses as much as digits as its factorization.

12166021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738010.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 12166021 is about 3487.9823680747. The cubic root of 12166021 is about 229.9938309625.

The spelling of 12166021 in words is "twelve million, one hundred sixty-six thousand, twenty-one".