25781237 has 2 divisors, whose sum is σ = 25781238. Its totient is φ = 25781236.

The previous prime is 25781227. The next prime is 25781257. The reversal of 25781237 is 73218752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15062161 + 10719076 = 3881^2 + 3274^2 .

It is a cyclic number.

It is not a de Polignac number, because 25781237 - 2⁸ = 25780981 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25781197 and 25781206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25781207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12890618 + 12890619.

It is an arithmetic number, because the mean of its divisors is an integer number (12890619).

Almost surely, 2^25781237 is an apocalyptic number.

It is an amenable number.

25781237 is a deficient number, since it is larger than the sum of its proper divisors (1).

25781237 is an equidigital number, since it uses as much as digits as its factorization.

25781237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 35.

The square root of 25781237 is about 5077.5227227458. The cubic root of 25781237 is about 295.4163879630.

Adding to 25781237 its reverse (73218752), we get a palindrome (98999989).

The spelling of 25781237 in words is "twenty-five million, seven hundred eighty-one thousand, two hundred thirty-seven".