12505639 has 2 divisors, whose sum is σ = 12505640. Its totient is φ = 12505638.

The previous prime is 12505637. The next prime is 12505643. The reversal of 12505639 is 93650521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12505639 - 2¹ = 12505637 is a prime.

Together with 12505637, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 12505639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12505631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6252819 + 6252820.

It is an arithmetic number, because the mean of its divisors is an integer number (6252820).

Almost surely, 2^12505639 is an apocalyptic number.

12505639 is a deficient number, since it is larger than the sum of its proper divisors (1).

12505639 is an equidigital number, since it uses as much as digits as its factorization.

12505639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 12505639 is about 3536.3312910416. The cubic root of 12505639 is about 232.1143349934.

It can be divided in two parts, 1250 and 5639, that added together give a square (6889 = 83²).

The spelling of 12505639 in words is "twelve million, five hundred five thousand, six hundred thirty-nine".