25439 has 2 divisors, whose sum is σ = 25440. Its totient is φ = 25438.

The previous prime is 25423. The next prime is 25447. The reversal of 25439 is 93452.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25439 - 2⁴ = 25423 is a prime.

It is a d-powerful number, because it can be written as 2¹³ + 5³ + 4⁷ + 3⁶ + 9 .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 25439.

It is not a weakly prime, because it can be changed into another prime (25409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12719 + 12720.

It is an arithmetic number, because the mean of its divisors is an integer number (12720).

2²⁵⁴³⁹ is an apocalyptic number.

25439 is a deficient number, since it is larger than the sum of its proper divisors (1).

25439 is an equidigital number, since it uses as much as digits as its factorization.

25439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 23.

The square root of 25439 is about 159.4960814566. The cubic root of 25439 is about 29.4103377347.

It can be divided in two parts, 2543 and 9, that added together give a palindrome (2552).

The spelling of 25439 in words is "twenty-five thousand, four hundred thirty-nine".