12805812909 has 32 divisors (see below), whose sum is σ = 19616916480. Its totient is φ = 8247744000.

The previous prime is 12805812881. The next prime is 12805812911. The reversal of 12805812909 is 90921850821.

12805812909 is a `hidden beast` number, since 1 + 280 + 5 + 81 + 290 + 9 = 666.

It is not a de Polignac number, because 12805812909 - 2¹¹ = 12805810861 is a prime.

It is a super-2 number, since 2×12805812909² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12805812959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 490309 + ... + 515765.

It is an arithmetic number, because the mean of its divisors is an integer number (613028640).

Almost surely, 2^12805812909 is an apocalyptic number.

It is an amenable number.

12805812909 is a deficient number, since it is larger than the sum of its proper divisors (6811103571).

12805812909 is a wasteful number, since it uses less digits than its factorization.

12805812909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26098 (or 26092 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 12805812909 in words is "twelve billion, eight hundred five million, eight hundred twelve thousand, nine hundred nine".