25920221 has 2 divisors, whose sum is σ = 25920222. Its totient is φ = 25920220.

The previous prime is 25920217. The next prime is 25920269. The reversal of 25920221 is 12202952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18705625 + 7214596 = 4325^2 + 2686^2 .

It is a cyclic number.

It is not a de Polignac number, because 25920221 - 2² = 25920217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25920211) 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, 12960110 + 12960111.

It is an arithmetic number, because the mean of its divisors is an integer number (12960111).

Almost surely, 2^25920221 is an apocalyptic number.

It is an amenable number.

25920221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25920221 is an equidigital number, since it uses as much as digits as its factorization.

25920221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 25920221 is about 5091.1905287467. The cubic root of 25920221 is about 295.9462900174.

The spelling of 25920221 in words is "twenty-five million, nine hundred twenty thousand, two hundred twenty-one".