25840861 has 2 divisors, whose sum is σ = 25840862. Its totient is φ = 25840860.

The previous prime is 25840853. The next prime is 25840873. The reversal of 25840861 is 16804852.

25840861 = 3594² + 3595².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 12916836 = 3595^2 + 3594^2 .

It is a cyclic number.

It is not a de Polignac number, because 25840861 - 2³ = 25840853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25840811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12920430 + 12920431.

It is an arithmetic number, because the mean of its divisors is an integer number (12920431).

Almost surely, 2^25840861 is an apocalyptic number.

25840861 is the 3595-th centered square number.

It is an amenable number.

25840861 is a deficient number, since it is larger than the sum of its proper divisors (1).

25840861 is an equidigital number, since it uses as much as digits as its factorization.

25840861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 25840861 is about 5083.3906991299. The cubic root of 25840861 is about 295.6439481022.

The spelling of 25840861 in words is "twenty-five million, eight hundred forty thousand, eight hundred sixty-one".