12661558 has 32 divisors (see below), whose sum is σ = 23720256. Its totient is φ = 4935168.

The previous prime is 12661499. The next prime is 12661589. The reversal of 12661558 is 85516621.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 12810 + ... + 13762.

It is an arithmetic number, because the mean of its divisors is an integer number (741258).

Almost surely, 2^12661558 is an apocalyptic number.

12661558 is a deficient number, since it is larger than the sum of its proper divisors (11058698).

12661558 is a wasteful number, since it uses less digits than its factorization.

12661558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048.

The product of its digits is 14400, while the sum is 34.

The square root of 12661558 is about 3558.3083059229. The cubic root of 12661558 is about 233.0750125341.

The spelling of 12661558 in words is "twelve million, six hundred sixty-one thousand, five hundred fifty-eight".