25684781 has 2 divisors, whose sum is σ = 25684782. Its totient is φ = 25684780.

The previous prime is 25684759. The next prime is 25684811. The reversal of 25684781 is 18748652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17222500 + 8462281 = 4150^2 + 2909^2 .

It is a cyclic number.

It is not a de Polignac number, because 25684781 - 2¹⁴ = 25668397 is a prime.

It is a super-3 number, since 3×25684781³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25684741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12842390 + 12842391.

It is an arithmetic number, because the mean of its divisors is an integer number (12842391).

Almost surely, 2^25684781 is an apocalyptic number.

It is an amenable number.

25684781 is a deficient number, since it is larger than the sum of its proper divisors (1).

25684781 is an equidigital number, since it uses as much as digits as its factorization.

25684781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107520, while the sum is 41.

The square root of 25684781 is about 5068.0154893212. The cubic root of 25684781 is about 295.0475112598.

The spelling of 25684781 in words is "twenty-five million, six hundred eighty-four thousand, seven hundred eighty-one".