12749309 has 8 divisors (see below), whose sum is σ = 13050072. Its totient is φ = 12450880.

The previous prime is 12749293. The next prime is 12749311. The reversal of 12749309 is 90394721.

It can be written as a sum of positive squares in 4 ways, for example, as 4853209 + 7896100 = 2203^2 + 2810^2 .

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 12749309 - 2⁴ = 12749293 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12749509) 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 7 ways as a sum of consecutive naturals, for example, 15119 + ... + 15939.

It is an arithmetic number, because the mean of its divisors is an integer number (1631259).

Almost surely, 2^12749309 is an apocalyptic number.

It is an amenable number.

12749309 is a deficient number, since it is larger than the sum of its proper divisors (300763).

12749309 is an equidigital number, since it uses as much as digits as its factorization.

12749309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 12749309 is about 3570.6174536066. The cubic root of 12749309 is about 233.6122159766.

The spelling of 12749309 in words is "twelve million, seven hundred forty-nine thousand, three hundred nine".