25166561 has 8 divisors (see below), whose sum is σ = 28805184. Its totient is φ = 21538800.

The previous prime is 25166527. The next prime is 25166593. The reversal of 25166561 is 16566152.

25166561 = T₂₆₇₈ + T₂₆₇₉ + ... + T₂₆₈₄.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25166561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25165561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3086 + ... + 7736.

It is an arithmetic number, because the mean of its divisors is an integer number (3600648).

Almost surely, 2^25166561 is an apocalyptic number.

It is an amenable number.

25166561 is a deficient number, since it is larger than the sum of its proper divisors (3638623).

25166561 is an equidigital number, since it uses as much as digits as its factorization.

25166561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5431.

The product of its digits is 10800, while the sum is 32.

The square root of 25166561 is about 5016.6284494668. The cubic root of 25166561 is about 293.0497067645.

The spelling of 25166561 in words is "twenty-five million, one hundred sixty-six thousand, five hundred sixty-one".