25663549 has 4 divisors (see below), whose sum is σ = 25674364. Its totient is φ = 25652736.

The previous prime is 25663541. The next prime is 25663559. The reversal of 25663549 is 94536652.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 18062500 + 7601049 = 4250^2 + 2757^2 .

It is a cyclic number.

It is not a de Polignac number, because 25663549 - 2³ = 25663541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25663541) 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, 132 + ... + 7165.

It is an arithmetic number, because the mean of its divisors is an integer number (6418591).

Almost surely, 2^25663549 is an apocalyptic number.

It is an amenable number.

25663549 is a deficient number, since it is larger than the sum of its proper divisors (10815).

25663549 is an equidigital number, since it uses as much as digits as its factorization.

25663549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10814.

The product of its digits is 194400, while the sum is 40.

The square root of 25663549 is about 5065.9203507359. The cubic root of 25663549 is about 294.9661897476.

The spelling of 25663549 in words is "twenty-five million, six hundred sixty-three thousand, five hundred forty-nine".