25639013 has 2 divisors, whose sum is σ = 25639014. Its totient is φ = 25639012.

The previous prime is 25638989. The next prime is 25639021. The reversal of 25639013 is 31093652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24930049 + 708964 = 4993^2 + 842^2 .

It is a cyclic number.

It is not a de Polignac number, because 25639013 - 2⁸ = 25638757 is a prime.

It is a super-2 number, since 2×25639013² = 1314717975228338, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25609013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12819506 + 12819507.

It is an arithmetic number, because the mean of its divisors is an integer number (12819507).

Almost surely, 2^25639013 is an apocalyptic number.

It is an amenable number.

25639013 is a deficient number, since it is larger than the sum of its proper divisors (1).

25639013 is an equidigital number, since it uses as much as digits as its factorization.

25639013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 25639013 is about 5063.4980991406. The cubic root of 25639013 is about 294.8721575713.

The spelling of 25639013 in words is "twenty-five million, six hundred thirty-nine thousand, thirteen".