12189381 has 4 divisors (see below), whose sum is σ = 16252512. Its totient is φ = 8126252.

The previous prime is 12189371. The next prime is 12189439. The reversal of 12189381 is 18398121.

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 a cyclic number.

It is not a de Polignac number, because 12189381 - 2⁵ = 12189349 is a prime.

It is a super-3 number, since 3×12189381³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12189371) 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, 2031561 + ... + 2031566.

It is an arithmetic number, because the mean of its divisors is an integer number (4063128).

Almost surely, 2^12189381 is an apocalyptic number.

It is an amenable number.

12189381 is a deficient number, since it is larger than the sum of its proper divisors (4063131).

12189381 is an equidigital number, since it uses as much as digits as its factorization.

12189381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4063130.

The product of its digits is 3456, while the sum is 33.

The square root of 12189381 is about 3491.3294029639. The cubic root of 12189381 is about 230.1409407111.

The spelling of 12189381 in words is "twelve million, one hundred eighty-nine thousand, three hundred eighty-one".