12189391 has 8 divisors (see below), whose sum is σ = 13255920. Its totient is φ = 11161728.

The previous prime is 12189371. The next prime is 12189439. The reversal of 12189391 is 19398121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12189391 is a prime.

It is a super-3 number, since 3×12189391³ (a number of 22 digits) contains 333 as substring.

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 7 ways as a sum of consecutive naturals, for example, 9061 + ... + 10318.

It is an arithmetic number, because the mean of its divisors is an integer number (1656990).

Almost surely, 2^12189391 is an apocalyptic number.

12189391 is a deficient number, since it is larger than the sum of its proper divisors (1066529).

12189391 is a wasteful number, since it uses less digits than its factorization.

12189391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19433.

The product of its digits is 3888, while the sum is 34.

The square root of 12189391 is about 3491.3308350828. The cubic root of 12189391 is about 230.1410036459.

It can be divided in two parts, 1218 and 9391, that added together give a square (10609 = 103²).

The spelling of 12189391 in words is "twelve million, one hundred eighty-nine thousand, three hundred ninety-one".