12128805 has 32 divisors (see below), whose sum is σ = 23224320. Its totient is φ = 5970240.

The previous prime is 12128801. The next prime is 12128819. The reversal of 12128805 is 50882121.

It is not a de Polignac number, because 12128805 - 2² = 12128801 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12128801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1701 + ... + 5210.

It is an arithmetic number, because the mean of its divisors is an integer number (725760).

Almost surely, 2^12128805 is an apocalyptic number.

12128805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12128805 is a deficient number, since it is larger than the sum of its proper divisors (11095515).

12128805 is a wasteful number, since it uses less digits than its factorization.

12128805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6938 (or 6932 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 12128805 is about 3482.6433925971. The cubic root of 12128805 is about 229.7590734879.

The spelling of 12128805 in words is "twelve million, one hundred twenty-eight thousand, eight hundred five".