12500809 has 2 divisors, whose sum is σ = 12500810. Its totient is φ = 12500808.

The previous prime is 12500779. The next prime is 12500819. The reversal of 12500809 is 90800521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11923209 + 577600 = 3453^2 + 760^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12500809 is a prime.

It is not a weakly prime, because it can be changed into another prime (12500819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6250404 + 6250405.

It is an arithmetic number, because the mean of its divisors is an integer number (6250405).

Almost surely, 2^12500809 is an apocalyptic number.

It is an amenable number.

12500809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12500809 is an equidigital number, since it uses as much as digits as its factorization.

12500809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 12500809 is about 3535.6483139588. The cubic root of 12500809 is about 232.0844482998.

The spelling of 12500809 in words is "twelve million, five hundred thousand, eight hundred nine".