25478861 has 2 divisors, whose sum is σ = 25478862. Its totient is φ = 25478860.

The previous prime is 25478857. The next prime is 25478863. The reversal of 25478861 is 16887452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24255625 + 1223236 = 4925^2 + 1106^2 .

It is a cyclic number.

It is not a de Polignac number, because 25478861 - 2² = 25478857 is a prime.

Together with 25478863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25478863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12739430 + 12739431.

It is an arithmetic number, because the mean of its divisors is an integer number (12739431).

Almost surely, 2^25478861 is an apocalyptic number.

It is an amenable number.

25478861 is a deficient number, since it is larger than the sum of its proper divisors (1).

25478861 is an equidigital number, since it uses as much as digits as its factorization.

25478861 is an evil number, because the sum of its binary digits is even.

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

The square root of 25478861 is about 5047.6589623310. The cubic root of 25478861 is about 294.2569098088.

The spelling of 25478861 in words is "twenty-five million, four hundred seventy-eight thousand, eight hundred sixty-one".