25643001 has 4 divisors (see below), whose sum is σ = 34190672. Its totient is φ = 17095332.

The previous prime is 25642973. The next prime is 25643063. The reversal of 25643001 is 10034652.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 25643001 - 2⁹ = 25642489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25643071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4273831 + ... + 4273836.

It is an arithmetic number, because the mean of its divisors is an integer number (8547668).

Almost surely, 2^25643001 is an apocalyptic number.

It is an amenable number.

25643001 is a deficient number, since it is larger than the sum of its proper divisors (8547671).

25643001 is an equidigital number, since it uses as much as digits as its factorization.

25643001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8547670.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 25643001 is about 5063.8918827321. The cubic root of 25643001 is about 294.8874453309.

Adding to 25643001 its reverse (10034652), we get a palindrome (35677653).

It can be divided in two parts, 2564 and 3001, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 25643001 in words is "twenty-five million, six hundred forty-three thousand, one".