12809391 has 16 divisors (see below), whose sum is σ = 19607808. Its totient is φ = 7286400.

The previous prime is 12809359. The next prime is 12809491. The reversal of 12809391 is 19390821.

12809391 is a nontrivial binomial coefficient, being equal to C(5062, 2).

It is not a de Polignac number, because 12809391 - 2⁵ = 12809359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12809351) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3796 + ... + 6326.

It is an arithmetic number, because the mean of its divisors is an integer number (1225488).

Almost surely, 2^12809391 is an apocalyptic number.

12809391 is the 5061-st triangular number and also the 2531-st hexagonal number.

12809391 is a deficient number, since it is larger than the sum of its proper divisors (6798417).

12809391 is a wasteful number, since it uses less digits than its factorization.

12809391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2782.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 12809391 is about 3579.0209555128. The cubic root of 12809391 is about 233.9786122610.

The spelling of 12809391 in words is "twelve million, eight hundred nine thousand, three hundred ninety-one".