12505809 has 8 divisors (see below), whose sum is σ = 16746912. Its totient is φ = 8300960.

The previous prime is 12505799. The next prime is 12505811. The reversal of 12505809 is 90850521.

12505809 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 12505809 - 2⁷ = 12505681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12505879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8247 + ... + 9644.

It is an arithmetic number, because the mean of its divisors is an integer number (2093364).

Almost surely, 2^12505809 is an apocalyptic number.

It is an amenable number.

12505809 is a deficient number, since it is larger than the sum of its proper divisors (4241103).

12505809 is a wasteful number, since it uses less digits than its factorization.

12505809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18127.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 12505809 is about 3536.3553271695. The cubic root of 12505809 is about 232.1153867658.

The spelling of 12505809 in words is "twelve million, five hundred five thousand, eight hundred nine".