25164221 has 4 divisors (see below), whose sum is σ = 25176444. Its totient is φ = 25152000.

The previous prime is 25164211. The next prime is 25164229. The reversal of 25164221 is 12246152.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 20124196 + 5040025 = 4486^2 + 2245^2 .

It is a cyclic number.

It is not a de Polignac number, because 25164221 - 2¹⁰ = 25163197 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 (25164229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2180 + ... + 7421.

It is an arithmetic number, because the mean of its divisors is an integer number (6294111).

Almost surely, 2^25164221 is an apocalyptic number.

It is an amenable number.

25164221 is a deficient number, since it is larger than the sum of its proper divisors (12223).

25164221 is an equidigital number, since it uses as much as digits as its factorization.

25164221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12222.

The product of its digits is 960, while the sum is 23.

The square root of 25164221 is about 5016.3952196772. The cubic root of 25164221 is about 293.0406238447.

The spelling of 25164221 in words is "twenty-five million, one hundred sixty-four thousand, two hundred twenty-one".