25309 has 2 divisors, whose sum is σ = 25310. Its totient is φ = 25308.

The previous prime is 25307. The next prime is 25321. The reversal of 25309 is 90352.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22500 + 2809 = 150^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 25309 - 2¹ = 25307 is a prime.

Together with 25307, it forms a pair of twin primes.

25309 is a lucky number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12654 + 12655.

It is an arithmetic number, because the mean of its divisors is an integer number (12655).

2²⁵³⁰⁹ is an apocalyptic number.

It is an amenable number.

25309 is a deficient number, since it is larger than the sum of its proper divisors (1).

25309 is an equidigital number, since it uses as much as digits as its factorization.

25309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 270, while the sum is 19.

The square root of 25309 is about 159.0880259479. The cubic root of 25309 is about 29.3601539588.

The spelling of 25309 in words is "twenty-five thousand, three hundred nine".