25128406646 has 16 divisors (see below), whose sum is σ = 43125854976. Its totient is φ = 10757170536.

The previous prime is 25128406643. The next prime is 25128406651. The reversal of 25128406646 is 64660482152.

It is a junction number, because it is equal to n+sod(n) for n = 25128406597 and 25128406606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25128406643) 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 in 7 ways as a sum of consecutive naturals, for example, 999356 + ... + 1024191.

It is an arithmetic number, because the mean of its divisors is an integer number (2695365936).

Almost surely, 2^25128406646 is an apocalyptic number.

25128406646 is a deficient number, since it is larger than the sum of its proper divisors (17997448330).

25128406646 is a wasteful number, since it uses less digits than its factorization.

25128406646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2024443.

The product of its (nonzero) digits is 552960, while the sum is 44.

Adding to 25128406646 its reverse (64660482152), we get a palindrome (89788888798).

The spelling of 25128406646 in words is "twenty-five billion, one hundred twenty-eight million, four hundred six thousand, six hundred forty-six".