12705309 has 16 divisors (see below), whose sum is σ = 18906240. Its totient is φ = 8432640.

The previous prime is 12705289. The next prime is 12705311. The reversal of 12705309 is 90350721.

12705309 is a `hidden beast` number, since 127 + 0 + 530 + 9 = 666.

12705309 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-12705309 is a prime.

It is a super-2 number, since 2×12705309² = 322849753570962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12705349) 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, 6024 + ... + 7854.

It is an arithmetic number, because the mean of its divisors is an integer number (1181640).

Almost surely, 2^12705309 is an apocalyptic number.

It is an amenable number.

12705309 is a deficient number, since it is larger than the sum of its proper divisors (6200931).

12705309 is a wasteful number, since it uses less digits than its factorization.

12705309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2097 (or 2091 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 12705309 is about 3564.4507290745. The cubic root of 12705309 is about 233.3431612640.

The spelling of 12705309 in words is "twelve million, seven hundred five thousand, three hundred nine".