25520021 has 16 divisors (see below), whose sum is σ = 27706560. Its totient is φ = 23431680.

The previous prime is 25520017. The next prime is 25520051. The reversal of 25520021 is 12002552.

It is a cyclic number.

It is not a de Polignac number, because 25520021 - 2² = 25520017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25520051) 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 15 ways as a sum of consecutive naturals, for example, 112310 + ... + 112536.

It is an arithmetic number, because the mean of its divisors is an integer number (1731660).

Almost surely, 2^25520021 is an apocalyptic number.

It is an amenable number.

25520021 is a deficient number, since it is larger than the sum of its proper divisors (2186539).

25520021 is a wasteful number, since it uses less digits than its factorization.

25520021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 25520021 is about 5051.7344546205. The cubic root of 25520021 is about 294.4152776721.

Adding to 25520021 its reverse (12002552), we get a palindrome (37522573).

The spelling of 25520021 in words is "twenty-five million, five hundred twenty thousand, twenty-one".