25861009 has 2 divisors, whose sum is σ = 25861010. Its totient is φ = 25861008.

The previous prime is 25861001. The next prime is 25861019. The reversal of 25861009 is 90016852.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 10627600 = 3903^2 + 3260^2 .

It is a cyclic number.

It is not a de Polignac number, because 25861009 - 2³ = 25861001 is a prime.

It is not a weakly prime, because it can be changed into another prime (25861001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12930504 + 12930505.

It is an arithmetic number, because the mean of its divisors is an integer number (12930505).

Almost surely, 2^25861009 is an apocalyptic number.

It is an amenable number.

25861009 is a deficient number, since it is larger than the sum of its proper divisors (1).

25861009 is an equidigital number, since it uses as much as digits as its factorization.

25861009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 25861009 is about 5085.3720611180. The cubic root of 25861009 is about 295.7207655479.

The spelling of 25861009 in words is "twenty-five million, eight hundred sixty-one thousand, nine".