25606409 has 2 divisors, whose sum is σ = 25606410. Its totient is φ = 25606408.

The previous prime is 25606381. The next prime is 25606411. The reversal of 25606409 is 90460652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25603600 + 2809 = 5060^2 + 53^2 .

It is a cyclic number.

It is not a de Polignac number, because 25606409 - 2¹⁶ = 25540873 is a prime.

Together with 25606411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25606499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12803204 + 12803205.

It is an arithmetic number, because the mean of its divisors is an integer number (12803205).

Almost surely, 2^25606409 is an apocalyptic number.

It is an amenable number.

25606409 is a deficient number, since it is larger than the sum of its proper divisors (1).

25606409 is an equidigital number, since it uses as much as digits as its factorization.

25606409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 25606409 is about 5060.2775615573. The cubic root of 25606409 is about 294.7471125869.

The spelling of 25606409 in words is "twenty-five million, six hundred six thousand, four hundred nine".