25543439 has 2 divisors, whose sum is σ = 25543440. Its totient is φ = 25543438.

The previous prime is 25543393. The next prime is 25543459. The reversal of 25543439 is 93434552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25543439 - 2²⁰ = 24494863 is a prime.

It is a Sophie Germain prime.

It is equal to p_1597733 and since 25543439 and 1597733 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 25543399 and 25543408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25543459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12771719 + 12771720.

It is an arithmetic number, because the mean of its divisors is an integer number (12771720).

Almost surely, 2^25543439 is an apocalyptic number.

25543439 is a deficient number, since it is larger than the sum of its proper divisors (1).

25543439 is an equidigital number, since it uses as much as digits as its factorization.

25543439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 35.

The square root of 25543439 is about 5054.0517409302. The cubic root of 25543439 is about 294.5053051468.

The spelling of 25543439 in words is "twenty-five million, five hundred forty-three thousand, four hundred thirty-nine".