25728181 has 2 divisors, whose sum is σ = 25728182. Its totient is φ = 25728180.

The previous prime is 25728169. The next prime is 25728211. The reversal of 25728181 is 18182752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17514225 + 8213956 = 4185^2 + 2866^2 .

It is a cyclic number.

It is not a de Polignac number, because 25728181 - 2¹⁵ = 25695413 is a prime.

It is a super-2 number, since 2×25728181² = 1323878595137522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25728581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12864090 + 12864091.

It is an arithmetic number, because the mean of its divisors is an integer number (12864091).

Almost surely, 2^25728181 is an apocalyptic number.

It is an amenable number.

25728181 is a deficient number, since it is larger than the sum of its proper divisors (1).

25728181 is an equidigital number, since it uses as much as digits as its factorization.

25728181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 34.

The square root of 25728181 is about 5072.2954369792. The cubic root of 25728181 is about 295.2135999700.

The spelling of 25728181 in words is "twenty-five million, seven hundred twenty-eight thousand, one hundred eighty-one".