25820321 has 2 divisors, whose sum is σ = 25820322. Its totient is φ = 25820320.

The previous prime is 25820287. The next prime is 25820323. The reversal of 25820321 is 12302852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 5017600 = 4561^2 + 2240^2 .

It is a cyclic number.

It is not a de Polignac number, because 25820321 - 2⁶ = 25820257 is a prime.

Together with 25820323, 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 (25820323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12910160 + 12910161.

It is an arithmetic number, because the mean of its divisors is an integer number (12910161).

Almost surely, 2^25820321 is an apocalyptic number.

It is an amenable number.

25820321 is a deficient number, since it is larger than the sum of its proper divisors (1).

25820321 is an equidigital number, since it uses as much as digits as its factorization.

25820321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 25820321 is about 5081.3699924331. The cubic root of 25820321 is about 295.5655949808.

The spelling of 25820321 in words is "twenty-five million, eight hundred twenty thousand, three hundred twenty-one".