25732561 has 4 divisors (see below), whose sum is σ = 26851392. Its totient is φ = 24613732.

The previous prime is 25732549. The next prime is 25732579. The reversal of 25732561 is 16523752.

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 25732561 - 2¹⁷ = 25601489 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25732261) 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, 559381 + ... + 559426.

It is an arithmetic number, because the mean of its divisors is an integer number (6712848).

Almost surely, 2^25732561 is an apocalyptic number.

It is an amenable number.

25732561 is a deficient number, since it is larger than the sum of its proper divisors (1118831).

25732561 is a wasteful number, since it uses less digits than its factorization.

25732561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118830.

The product of its digits is 12600, while the sum is 31.

The square root of 25732561 is about 5072.7271757902. The cubic root of 25732561 is about 295.2303515390.

The spelling of 25732561 in words is "twenty-five million, seven hundred thirty-two thousand, five hundred sixty-one".