25320221 has 2 divisors, whose sum is σ = 25320222. Its totient is φ = 25320220.

The previous prime is 25320209. The next prime is 25320227. The reversal of 25320221 is 12202352.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25300900 + 19321 = 5030^2 + 139^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25320221 is a prime.

It is a super-2 number, since 2×25320221² = 1282227182977682, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25320221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25320227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12660110 + 12660111.

It is an arithmetic number, because the mean of its divisors is an integer number (12660111).

Almost surely, 2^25320221 is an apocalyptic number.

It is an amenable number.

25320221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25320221 is an equidigital number, since it uses as much as digits as its factorization.

25320221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 25320221 is about 5031.9202100192. The cubic root of 25320221 is about 293.6449235768.

Adding to 25320221 its reverse (12202352), we get a palindrome (37522573).

The spelling of 25320221 in words is "twenty-five million, three hundred twenty thousand, two hundred twenty-one".