25638989 has 2 divisors, whose sum is σ = 25638990. Its totient is φ = 25638988.

The previous prime is 25638973. The next prime is 25639013. The reversal of 25638989 is 98983652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18852964 + 6786025 = 4342^2 + 2605^2 .

It is a cyclic number.

It is not a de Polignac number, because 25638989 - 2⁴ = 25638973 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25638589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12819494 + 12819495.

It is an arithmetic number, because the mean of its divisors is an integer number (12819495).

Almost surely, 2^25638989 is an apocalyptic number.

It is an amenable number.

25638989 is a deficient number, since it is larger than the sum of its proper divisors (1).

25638989 is an equidigital number, since it uses as much as digits as its factorization.

25638989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 50.

The square root of 25638989 is about 5063.4957292369. The cubic root of 25638989 is about 294.8720655639.

The spelling of 25638989 in words is "twenty-five million, six hundred thirty-eight thousand, nine hundred eighty-nine".