25555521 has 4 divisors (see below), whose sum is σ = 34074032. Its totient is φ = 17037012.

The previous prime is 25555499. The next prime is 25555529. The reversal of 25555521 is 12555552.

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 not a de Polignac number, because 25555521 - 2⁵ = 25555489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25555529) 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, 4259251 + ... + 4259256.

It is an arithmetic number, because the mean of its divisors is an integer number (8518508).

Almost surely, 2^25555521 is an apocalyptic number.

It is an amenable number.

25555521 is a deficient number, since it is larger than the sum of its proper divisors (8518511).

25555521 is an equidigital number, since it uses as much as digits as its factorization.

25555521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8518510.

The product of its digits is 12500, while the sum is 30.

The square root of 25555521 is about 5055.2468782444. The cubic root of 25555521 is about 294.5517313183.

The spelling of 25555521 in words is "twenty-five million, five hundred fifty-five thousand, five hundred twenty-one".