25643617 has 4 divisors (see below), whose sum is σ = 25792020. Its totient is φ = 25495216.

The previous prime is 25643593. The next prime is 25643621. The reversal of 25643617 is 71634652.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 25010001 + 633616 = 5001^2 + 796^2 .

It is a cyclic number.

It is not a de Polignac number, because 25643617 - 2⁷ = 25643489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25643677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73942 + ... + 74287.

It is an arithmetic number, because the mean of its divisors is an integer number (6448005).

Almost surely, 2^25643617 is an apocalyptic number.

It is an amenable number.

25643617 is a deficient number, since it is larger than the sum of its proper divisors (148403).

25643617 is a wasteful number, since it uses less digits than its factorization.

25643617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148402.

The product of its digits is 30240, while the sum is 34.

The square root of 25643617 is about 5063.9527051504. The cubic root of 25643617 is about 294.8898065887.

The spelling of 25643617 in words is "twenty-five million, six hundred forty-three thousand, six hundred seventeen".