12891805 has 16 divisors (see below), whose sum is σ = 16254720. Its totient is φ = 9801792.

The previous prime is 12891803. The next prime is 12891811. The reversal of 12891805 is 50819821.

It is a cyclic number.

It is not a de Polignac number, because 12891805 - 2¹ = 12891803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12891803) 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 15 ways as a sum of consecutive naturals, for example, 9052 + ... + 10378.

It is an arithmetic number, because the mean of its divisors is an integer number (1015920).

Almost surely, 2^12891805 is an apocalyptic number.

It is an amenable number.

12891805 is a deficient number, since it is larger than the sum of its proper divisors (3362915).

12891805 is a wasteful number, since it uses less digits than its factorization.

12891805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1428.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 12891805 is about 3590.5159796330. The cubic root of 12891805 is about 234.4793361830.

The spelling of 12891805 in words is "twelve million, eight hundred ninety-one thousand, eight hundred five".