25404521 has 4 divisors (see below), whose sum is σ = 25637700. Its totient is φ = 25171344.

The previous prime is 25404517. The next prime is 25404523. The reversal of 25404521 is 12540452.

It is a happy number.

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 11424400 + 13980121 = 3380^2 + 3739^2 .

It is a cyclic number.

It is not a de Polignac number, because 25404521 - 2² = 25404517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25404523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116426 + ... + 116643.

It is an arithmetic number, because the mean of its divisors is an integer number (6409425).

Almost surely, 2^25404521 is an apocalyptic number.

It is an amenable number.

25404521 is a deficient number, since it is larger than the sum of its proper divisors (233179).

25404521 is a wasteful number, since it uses less digits than its factorization.

25404521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233178.

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

The square root of 25404521 is about 5040.2897734158. The cubic root of 25404521 is about 293.9704452991.

Adding to 25404521 its reverse (12540452), we get a palindrome (37944973).

The spelling of 25404521 in words is "twenty-five million, four hundred four thousand, five hundred twenty-one".