25166221 has 4 divisors (see below), whose sum is σ = 25578844. Its totient is φ = 24753600.

The previous prime is 25166201. The next prime is 25166231. The reversal of 25166221 is 12266152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10150596 + 15015625 = 3186^2 + 3875^2 .

It is a cyclic number.

It is not a de Polignac number, because 25166221 - 2⁵ = 25166189 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 (25166201) 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 3 ways as a sum of consecutive naturals, for example, 206220 + ... + 206341.

It is an arithmetic number, because the mean of its divisors is an integer number (6394711).

Almost surely, 2^25166221 is an apocalyptic number.

It is an amenable number.

25166221 is a deficient number, since it is larger than the sum of its proper divisors (412623).

25166221 is an equidigital number, since it uses as much as digits as its factorization.

25166221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412622.

The product of its digits is 1440, while the sum is 25.

The square root of 25166221 is about 5016.5945620510. The cubic root of 25166221 is about 293.0483870590.

The spelling of 25166221 in words is "twenty-five million, one hundred sixty-six thousand, two hundred twenty-one".