12128551 has 4 divisors (see below), whose sum is σ = 12144112. Its totient is φ = 12112992.

The previous prime is 12128513. The next prime is 12128561. The reversal of 12128551 is 15582121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15582121 = 2243 ⋅6947.

It is a cyclic number.

It is not a de Polignac number, because 12128551 - 2⁷ = 12128423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12128561) 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, 6546 + ... + 8191.

It is an arithmetic number, because the mean of its divisors is an integer number (3036028).

Almost surely, 2^12128551 is an apocalyptic number.

12128551 is a deficient number, since it is larger than the sum of its proper divisors (15561).

12128551 is an equidigital number, since it uses as much as digits as its factorization.

12128551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15560.

The product of its digits is 800, while the sum is 25.

The square root of 12128551 is about 3482.6069258531. The cubic root of 12128551 is about 229.7574696143.

The spelling of 12128551 in words is "twelve million, one hundred twenty-eight thousand, five hundred fifty-one".