25667643 has 4 divisors (see below), whose sum is σ = 34223528. Its totient is φ = 17111760.

The previous prime is 25667627. The next prime is 25667683. The reversal of 25667643 is 34676652.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 25667643 - 2⁴ = 25667627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25667683) 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 in 3 ways as a sum of consecutive naturals, for example, 4277938 + ... + 4277943.

It is an arithmetic number, because the mean of its divisors is an integer number (8555882).

Almost surely, 2^25667643 is an apocalyptic number.

25667643 is a deficient number, since it is larger than the sum of its proper divisors (8555885).

25667643 is an equidigital number, since it uses as much as digits as its factorization.

25667643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8555884.

The product of its digits is 181440, while the sum is 39.

The square root of 25667643 is about 5066.3244072996. The cubic root of 25667643 is about 294.9818738264.

Subtracting 25667643 from its reverse (34676652), we obtain a palindrome (9009009).

The spelling of 25667643 in words is "twenty-five million, six hundred sixty-seven thousand, six hundred forty-three".