12787809 has 12 divisors (see below), whose sum is σ = 17294256. Its totient is φ = 8404968.

The previous prime is 12787799. The next prime is 12787823. The reversal of 12787809 is 90878721.

It is not a de Polignac number, because 12787809 - 2¹¹ = 12785761 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12787889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18382 + ... + 19064.

It is an arithmetic number, because the mean of its divisors is an integer number (1441188).

Almost surely, 2^12787809 is an apocalyptic number.

It is an amenable number.

12787809 is a deficient number, since it is larger than the sum of its proper divisors (4506447).

12787809 is an frugal number, since it uses more digits than its factorization.

12787809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844 (or 765 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 12787809 is about 3576.0046140910. The cubic root of 12787809 is about 233.8471315088.

The spelling of 12787809 in words is "twelve million, seven hundred eighty-seven thousand, eight hundred nine".