12165421 has 4 divisors (see below), whose sum is σ = 12881052. Its totient is φ = 11449792.

The previous prime is 12165407. The next prime is 12165427. The reversal of 12165421 is 12456121.

12165421 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 an emirpimes, since its reverse is a distinct semiprime: 12456121 = 17 ⋅732713.

It can be written as a sum of positive squares in 2 ways, for example, as 9796900 + 2368521 = 3130^2 + 1539^2 .

It is a cyclic number.

It is not a de Polignac number, because 12165421 - 2⁹ = 12164909 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12165392 and 12165401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12165427) 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, 357790 + ... + 357823.

It is an arithmetic number, because the mean of its divisors is an integer number (3220263).

Almost surely, 2^12165421 is an apocalyptic number.

It is an amenable number.

12165421 is a deficient number, since it is larger than the sum of its proper divisors (715631).

12165421 is an equidigital number, since it uses as much as digits as its factorization.

12165421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715630.

The product of its digits is 480, while the sum is 22.

The square root of 12165421 is about 3487.8963574051. The cubic root of 12165421 is about 229.9900499791.

The spelling of 12165421 in words is "twelve million, one hundred sixty-five thousand, four hundred twenty-one".