25207221 has 8 divisors (see below), whose sum is σ = 36195040. Its totient is φ = 15512112.

The previous prime is 25207211. The next prime is 25207229. The reversal of 25207221 is 12270252.

It is a happy number.

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

It is not a de Polignac number, because 25207221 - 2⁶ = 25207157 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 (25207229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323131 + ... + 323208.

It is an arithmetic number, because the mean of its divisors is an integer number (4524380).

Almost surely, 2^25207221 is an apocalyptic number.

It is an amenable number.

25207221 is a deficient number, since it is larger than the sum of its proper divisors (10987819).

25207221 is a wasteful number, since it uses less digits than its factorization.

25207221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646355.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 25207221 is about 5020.6793365042. The cubic root of 25207221 is about 293.2074423916.

Adding to 25207221 its reverse (12270252), we get a palindrome (37477473).

The spelling of 25207221 in words is "twenty-five million, two hundred seven thousand, two hundred twenty-one".