25581321 has 12 divisors (see below), whose sum is σ = 36994672. Its totient is φ = 17033976.

The previous prime is 25581307. The next prime is 25581329. The reversal of 25581321 is 12318552.

It is a happy number.

It is not a de Polignac number, because 25581321 - 2⁹ = 25580809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25581329) 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 11 ways as a sum of consecutive naturals, for example, 13770 + ... + 15516.

Almost surely, 2^25581321 is an apocalyptic number.

It is an amenable number.

25581321 is a deficient number, since it is larger than the sum of its proper divisors (11413351).

25581321 is a wasteful number, since it uses less digits than its factorization.

25581321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3380 (or 3377 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 25581321 is about 5057.7980386726. The cubic root of 25581321 is about 294.6508211747.

Adding to 25581321 its reverse (12318552), we get a palindrome (37899873).

The spelling of 25581321 in words is "twenty-five million, five hundred eighty-one thousand, three hundred twenty-one".