25240005521 has 2 divisors, whose sum is σ = 25240005522. Its totient is φ = 25240005520.

The previous prime is 25240005509. The next prime is 25240005523. The reversal of 25240005521 is 12550004252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25237770496 + 2235025 = 158864^2 + 1495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25240005521 is a prime.

It is a super-2 number, since 2×25240005521² (a number of 22 digits) contains 22 as substring.

Together with 25240005523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25240005523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12620002760 + 12620002761.

It is an arithmetic number, because the mean of its divisors is an integer number (12620002761).

Almost surely, 2^25240005521 is an apocalyptic number.

It is an amenable number.

25240005521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25240005521 is an equidigital number, since it uses as much as digits as its factorization.

25240005521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4000, while the sum is 26.

Adding to 25240005521 its reverse (12550004252), we get a palindrome (37790009773).

The spelling of 25240005521 in words is "twenty-five billion, two hundred forty million, five thousand, five hundred twenty-one".