25760221 has 2 divisors, whose sum is σ = 25760222. Its totient is φ = 25760220.

The previous prime is 25760209. The next prime is 25760243. The reversal of 25760221 is 12206752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16088121 + 9672100 = 4011^2 + 3110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25760221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25760201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12880110 + 12880111.

It is an arithmetic number, because the mean of its divisors is an integer number (12880111).

Almost surely, 2^25760221 is an apocalyptic number.

It is an amenable number.

25760221 is a deficient number, since it is larger than the sum of its proper divisors (1).

25760221 is an equidigital number, since it uses as much as digits as its factorization.

25760221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 25760221 is about 5075.4527876831. The cubic root of 25760221 is about 295.3360949635.

Adding to 25760221 its reverse (12206752), we get a palindrome (37966973).

The spelling of 25760221 in words is "twenty-five million, seven hundred sixty thousand, two hundred twenty-one".