25224221 has 4 divisors (see below), whose sum is σ = 27517344. Its totient is φ = 22931100.

The previous prime is 25224217. The next prime is 25224223. The reversal of 25224221 is 12242252.

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 25224221 - 2² = 25224217 is a prime.

It is a super-2 number, since 2×25224221² = 1272522650113682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 25224193 and 25224202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25224223) 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, 1146545 + ... + 1146566.

It is an arithmetic number, because the mean of its divisors is an integer number (6879336).

Almost surely, 2^25224221 is an apocalyptic number.

It is an amenable number.

25224221 is a deficient number, since it is larger than the sum of its proper divisors (2293123).

25224221 is a wasteful number, since it uses less digits than its factorization.

25224221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2293122.

The product of its digits is 640, while the sum is 20.

The square root of 25224221 is about 5022.3720491417. The cubic root of 25224221 is about 293.2733415825.

Adding to 25224221 its reverse (12242252), we get a palindrome (37466473).

The spelling of 25224221 in words is "twenty-five million, two hundred twenty-four thousand, two hundred twenty-one".