25409221 has 2 divisors, whose sum is σ = 25409222. Its totient is φ = 25409220.

The previous prime is 25409171. The next prime is 25409239. The reversal of 25409221 is 12290452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21986721 + 3422500 = 4689^2 + 1850^2 .

It is a cyclic number.

It is not a de Polignac number, because 25409221 - 2¹³ = 25401029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25409261) 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, 12704610 + 12704611.

It is an arithmetic number, because the mean of its divisors is an integer number (12704611).

Almost surely, 2^25409221 is an apocalyptic number.

It is an amenable number.

25409221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25409221 is an equidigital number, since it uses as much as digits as its factorization.

25409221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 25409221 is about 5040.7559948881. The cubic root of 25409221 is about 293.9885729898.

Adding to 25409221 its reverse (12290452), we get a palindrome (37699673).

The spelling of 25409221 in words is "twenty-five million, four hundred nine thousand, two hundred twenty-one".