25507561 has 4 divisors (see below), whose sum is σ = 25536592. Its totient is φ = 25478532.

The previous prime is 25507423. The next prime is 25507567. The reversal of 25507561 is 16570552.

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 a cyclic number.

It is not a de Polignac number, because 25507561 - 2⁹ = 25507049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25507567) 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, 13155 + ... + 14968.

It is an arithmetic number, because the mean of its divisors is an integer number (6384148).

Almost surely, 2^25507561 is an apocalyptic number.

It is an amenable number.

25507561 is a deficient number, since it is larger than the sum of its proper divisors (29031).

25507561 is an equidigital number, since it uses as much as digits as its factorization.

25507561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29030.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 25507561 is about 5050.5010642510. The cubic root of 25507561 is about 294.3673543632.

The spelling of 25507561 in words is "twenty-five million, five hundred seven thousand, five hundred sixty-one".