12991655 has 8 divisors (see below), whose sum is σ = 16507152. Its totient is φ = 9781888.

The previous prime is 12991613. The next prime is 12991661. The reversal of 12991655 is 55619921.

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

It is a cyclic number.

It is not a de Polignac number, because 12991655 - 2¹⁰ = 12990631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 76337 + ... + 76506.

It is an arithmetic number, because the mean of its divisors is an integer number (2063394).

Almost surely, 2^12991655 is an apocalyptic number.

12991655 is a deficient number, since it is larger than the sum of its proper divisors (3515497).

12991655 is a wasteful number, since it uses less digits than its factorization.

12991655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152865.

The product of its digits is 24300, while the sum is 38.

The square root of 12991655 is about 3604.3938464047. The cubic root of 12991655 is about 235.0831454694.

The spelling of 12991655 in words is "twelve million, nine hundred ninety-one thousand, six hundred fifty-five".