25638857 has 2 divisors, whose sum is σ = 25638858. Its totient is φ = 25638856.

The previous prime is 25638827. The next prime is 25638883. The reversal of 25638857 is 75883652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22762441 + 2876416 = 4771^2 + 1696^2 .

It is a cyclic number.

It is not a de Polignac number, because 25638857 - 2¹² = 25634761 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25638827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12819428 + 12819429.

It is an arithmetic number, because the mean of its divisors is an integer number (12819429).

Almost surely, 2^25638857 is an apocalyptic number.

It is an amenable number.

25638857 is a deficient number, since it is larger than the sum of its proper divisors (1).

25638857 is an equidigital number, since it uses as much as digits as its factorization.

25638857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 403200, while the sum is 44.

The square root of 25638857 is about 5063.4826947468. The cubic root of 25638857 is about 294.8715595224.

The spelling of 25638857 in words is "twenty-five million, six hundred thirty-eight thousand, eight hundred fifty-seven".