25520647 has 2 divisors, whose sum is σ = 25520648. Its totient is φ = 25520646.

The previous prime is 25520623. The next prime is 25520653. The reversal of 25520647 is 74602552.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25520647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25520617) 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 as a sum of consecutive naturals, namely, 12760323 + 12760324.

It is an arithmetic number, because the mean of its divisors is an integer number (12760324).

Almost surely, 2^25520647 is an apocalyptic number.

25520647 is a deficient number, since it is larger than the sum of its proper divisors (1).

25520647 is an equidigital number, since it uses as much as digits as its factorization.

25520647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 25520647 is about 5051.7964131584. The cubic root of 25520647 is about 294.4176849645.

It can be divided in two parts, 255 and 20647, that added together give a palindrome (20902).

The spelling of 25520647 in words is "twenty-five million, five hundred twenty thousand, six hundred forty-seven".