25425221 has 4 divisors (see below), whose sum is σ = 25438092. Its totient is φ = 25412352.

The previous prime is 25425209. The next prime is 25425223. The reversal of 25425221 is 12252452.

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 20802721 + 4622500 = 4561^2 + 2150^2 .

It is a cyclic number.

It is not a de Polignac number, because 25425221 - 2¹⁴ = 25408837 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 (25425223) 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, 2780 + ... + 7653.

It is an arithmetic number, because the mean of its divisors is an integer number (6359523).

Almost surely, 2^25425221 is an apocalyptic number.

It is an amenable number.

25425221 is a deficient number, since it is larger than the sum of its proper divisors (12871).

25425221 is a wasteful number, since it uses less digits than its factorization.

25425221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12870.

The product of its digits is 1600, while the sum is 23.

The square root of 25425221 is about 5042.3428086555. The cubic root of 25425221 is about 294.0502675244.

Adding to 25425221 its reverse (12252452), we get a palindrome (37677673).

The spelling of 25425221 in words is "twenty-five million, four hundred twenty-five thousand, two hundred twenty-one".