25643489 has 2 divisors, whose sum is σ = 25643490. Its totient is φ = 25643488.

The previous prime is 25643441. The next prime is 25643503. The reversal of 25643489 is 98434652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22165264 + 3478225 = 4708^2 + 1865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25643489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25643419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12821744 + 12821745.

It is an arithmetic number, because the mean of its divisors is an integer number (12821745).

Almost surely, 2^25643489 is an apocalyptic number.

It is an amenable number.

25643489 is a deficient number, since it is larger than the sum of its proper divisors (1).

25643489 is an equidigital number, since it uses as much as digits as its factorization.

25643489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 41.

The square root of 25643489 is about 5063.9400667859. The cubic root of 25643489 is about 294.8893159408.

The spelling of 25643489 in words is "twenty-five million, six hundred forty-three thousand, four hundred eighty-nine".