12129547 has 4 divisors (see below), whose sum is σ = 12138256. Its totient is φ = 12120840.

The previous prime is 12129539. The next prime is 12129571. The reversal of 12129547 is 74592121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 74592121 = 4027 ⋅18523.

It is a cyclic number.

It is not a de Polignac number, because 12129547 - 2³ = 12129539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12121547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1743 + ... + 5224.

It is an arithmetic number, because the mean of its divisors is an integer number (3034564).

Almost surely, 2^12129547 is an apocalyptic number.

12129547 is a deficient number, since it is larger than the sum of its proper divisors (8709).

12129547 is an equidigital number, since it uses as much as digits as its factorization.

12129547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8708.

The product of its digits is 5040, while the sum is 31.

The square root of 12129547 is about 3482.7499192448. The cubic root of 12129547 is about 229.7637586913.

The spelling of 12129547 in words is "twelve million, one hundred twenty-nine thousand, five hundred forty-seven".