12538809 has 12 divisors (see below), whose sum is σ = 19177236. Its totient is φ = 7867392.

The previous prime is 12538763. The next prime is 12538811. The reversal of 12538809 is 90883521.

It can be written as a sum of positive squares in 2 ways, for example, as 6487209 + 6051600 = 2547^2 + 2460^2 .

It is not a de Polignac number, because 12538809 - 2⁹ = 12538297 is a prime.

It is a super-2 number, since 2×12538809² = 314443462276962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12538829) 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, 40824 + ... + 41129.

It is an arithmetic number, because the mean of its divisors is an integer number (1598103).

Almost surely, 2^12538809 is an apocalyptic number.

It is an amenable number.

12538809 is a deficient number, since it is larger than the sum of its proper divisors (6638427).

12538809 is a wasteful number, since it uses less digits than its factorization.

12538809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81976 (or 81973 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 12538809 is about 3541.0180739443. The cubic root of 12538809 is about 232.3193741054.

The spelling of 12538809 in words is "twelve million, five hundred thirty-eight thousand, eight hundred nine".