12188421 has 16 divisors (see below), whose sum is σ = 20636800. Its totient is φ = 6964704.

The previous prime is 12188411. The next prime is 12188431. The reversal of 12188421 is 12488121.

It is an interprime number because it is at equal distance from previous prime (12188411) and next prime (12188431).

It is not a de Polignac number, because 12188421 - 2⁵ = 12188389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12188411) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32056 + ... + 32433.

It is an arithmetic number, because the mean of its divisors is an integer number (1289800).

Almost surely, 2^12188421 is an apocalyptic number.

It is an amenable number.

12188421 is a deficient number, since it is larger than the sum of its proper divisors (8448379).

12188421 is an equidigital number, since it uses as much as digits as its factorization.

12188421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64505 (or 64499 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 12188421 is about 3491.1919168101. The cubic root of 12188421 is about 230.1348988100.

The spelling of 12188421 in words is "twelve million, one hundred eighty-eight thousand, four hundred twenty-one".