12509531 has 2 divisors, whose sum is σ = 12509532. Its totient is φ = 12509530.

The previous prime is 12509513. The next prime is 12509533. The reversal of 12509531 is 13590521.

Together with previous prime (12509513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12509531 is a prime.

It is a super-2 number, since 2×12509531² = 312976731679922, which contains 22 as substring.

Together with 12509533, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12509531.

It is not a weakly prime, because it can be changed into another prime (12509533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6254765 + 6254766.

It is an arithmetic number, because the mean of its divisors is an integer number (6254766).

Almost surely, 2^12509531 is an apocalyptic number.

12509531 is a deficient number, since it is larger than the sum of its proper divisors (1).

12509531 is an equidigital number, since it uses as much as digits as its factorization.

12509531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 12509531 is about 3536.8815360427. The cubic root of 12509531 is about 232.1384120062.

The spelling of 12509531 in words is "twelve million, five hundred nine thousand, five hundred thirty-one".