25217989 has 2 divisors, whose sum is σ = 25217990. Its totient is φ = 25217988.

The previous prime is 25217981. The next prime is 25218013. The reversal of 25217989 is 98971252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22877089 + 2340900 = 4783^2 + 1530^2 .

It is a cyclic number.

It is not a de Polignac number, because 25217989 - 2³ = 25217981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25217981) 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, 12608994 + 12608995.

It is an arithmetic number, because the mean of its divisors is an integer number (12608995).

Almost surely, 2^25217989 is an apocalyptic number.

It is an amenable number.

25217989 is a deficient number, since it is larger than the sum of its proper divisors (1).

25217989 is an equidigital number, since it uses as much as digits as its factorization.

25217989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 25217989 is about 5021.7515868470. The cubic root of 25217989 is about 293.2491871530.

The spelling of 25217989 in words is "twenty-five million, two hundred seventeen thousand, nine hundred eighty-nine".