25520521 has 6 divisors (see below), whose sum is σ = 27634830. Its totient is φ = 23557248.

The previous prime is 25520489. The next prime is 25520527. The reversal of 25520521 is 12502552.

It can be written as a sum of positive squares in 3 ways, for example, as 2143296 + 23377225 = 1464^2 + 4835^2 .

It is not a de Polignac number, because 25520521 - 2⁵ = 25520489 is a prime.

It is a super-2 number, since 2×25520521² = 1302593984222882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25520492 and 25520501.

It is not an unprimeable number, because it can be changed into a prime (25520527) 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 5 ways as a sum of consecutive naturals, for example, 75336 + ... + 75673.

It is an arithmetic number, because the mean of its divisors is an integer number (4605805).

Almost surely, 2^25520521 is an apocalyptic number.

It is an amenable number.

25520521 is a deficient number, since it is larger than the sum of its proper divisors (2114309).

25520521 is a wasteful number, since it uses less digits than its factorization.

25520521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151035 (or 151022 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 25520521 is about 5051.7839423317. The cubic root of 25520521 is about 294.4172004327.

The spelling of 25520521 in words is "twenty-five million, five hundred twenty thousand, five hundred twenty-one".