25642224581 has 2 divisors, whose sum is σ = 25642224582. Its totient is φ = 25642224580.

The previous prime is 25642224563. The next prime is 25642224689. The reversal of 25642224581 is 18542224652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22543521025 + 3098703556 = 150145^2 + 55666^2 .

It is a cyclic number.

It is not a de Polignac number, because 25642224581 - 2¹⁰ = 25642223557 is a prime.

It is a super-2 number, since 2×25642224581² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25642224541) 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, 12821112290 + 12821112291.

It is an arithmetic number, because the mean of its divisors is an integer number (12821112291).

Almost surely, 2^25642224581 is an apocalyptic number.

It is an amenable number.

25642224581 is a deficient number, since it is larger than the sum of its proper divisors (1).

25642224581 is an equidigital number, since it uses as much as digits as its factorization.

25642224581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 307200, while the sum is 41.

The spelling of 25642224581 in words is "twenty-five billion, six hundred forty-two million, two hundred twenty-four thousand, five hundred eighty-one".