25666261 has 4 divisors (see below), whose sum is σ = 25915552. Its totient is φ = 25416972.

The previous prime is 25666253. The next prime is 25666279. The reversal of 25666261 is 16266652.

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 25666261 - 2³ = 25666253 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 (25666241) 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, 124491 + ... + 124696.

It is an arithmetic number, because the mean of its divisors is an integer number (6478888).

Almost surely, 2^25666261 is an apocalyptic number.

It is an amenable number.

25666261 is a deficient number, since it is larger than the sum of its proper divisors (249291).

25666261 is a wasteful number, since it uses less digits than its factorization.

25666261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249290.

The product of its digits is 25920, while the sum is 34.

The square root of 25666261 is about 5066.1880146714. The cubic root of 25666261 is about 294.9765795828.

The spelling of 25666261 in words is "twenty-five million, six hundred sixty-six thousand, two hundred sixty-one".