25644643 has 2 divisors, whose sum is σ = 25644644. Its totient is φ = 25644642.

The previous prime is 25644629. The next prime is 25644649. The reversal of 25644643 is 34644652.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25644643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25644599 and 25644608.

It is not a weakly prime, because it can be changed into another prime (25644649) 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 as a sum of consecutive naturals, namely, 12822321 + 12822322.

It is an arithmetic number, because the mean of its divisors is an integer number (12822322).

Almost surely, 2^25644643 is an apocalyptic number.

25644643 is a deficient number, since it is larger than the sum of its proper divisors (1).

25644643 is an equidigital number, since it uses as much as digits as its factorization.

25644643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 34.

The square root of 25644643 is about 5064.0540084008. The cubic root of 25644643 is about 294.8937393790.

Subtracting 25644643 from its reverse (34644652), we obtain a palindrome (9000009).

The spelling of 25644643 in words is "twenty-five million, six hundred forty-four thousand, six hundred forty-three".