12991055 has 32 divisors (see below), whose sum is σ = 19934208. Its totient is φ = 7891200.

The previous prime is 12991051. The next prime is 12991057. The reversal of 12991055 is 55019921.

It is not a de Polignac number, because 12991055 - 2² = 12991051 is a prime.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12991051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15374 + ... + 16196.

It is an arithmetic number, because the mean of its divisors is an integer number (622944).

Almost surely, 2^12991055 is an apocalyptic number.

12991055 is a deficient number, since it is larger than the sum of its proper divisors (6943153).

12991055 is a wasteful number, since it uses less digits than its factorization.

12991055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887.

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 12991055 is about 3604.3106136958. The cubic root of 12991055 is about 235.0795264268.

The spelling of 12991055 in words is "twelve million, nine hundred ninety-one thousand, fifty-five".