25638257 has 8 divisors (see below), whose sum is σ = 26166696. Its totient is φ = 25114752.

The previous prime is 25638251. The next prime is 25638259. The reversal of 25638257 is 75283652.

It can be written as a sum of positive squares in 4 ways, for example, as 5424241 + 20214016 = 2329^2 + 4496^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25638257 - 2⁴ = 25638241 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25638257.

It is not an unprimeable number, because it can be changed into a prime (25638251) 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 in 7 ways as a sum of consecutive naturals, for example, 10343 + ... + 12579.

It is an arithmetic number, because the mean of its divisors is an integer number (3270837).

Almost surely, 2^25638257 is an apocalyptic number.

It is an amenable number.

25638257 is a deficient number, since it is larger than the sum of its proper divisors (528439).

25638257 is a wasteful number, since it uses less digits than its factorization.

25638257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2467.

The product of its digits is 100800, while the sum is 38.

The square root of 25638257 is about 5063.4234466416. The cubic root of 25638257 is about 294.8692593118.

The spelling of 25638257 in words is "twenty-five million, six hundred thirty-eight thousand, two hundred fifty-seven".