25128802805 has 4 divisors (see below), whose sum is σ = 30154563372. Its totient is φ = 20103042240.

The previous prime is 25128802801. The next prime is 25128802823. The reversal of 25128802805 is 50820882152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6005785009 + 19123017796 = 77497^2 + 138286^2 .

It is not a de Polignac number, because 25128802805 - 2² = 25128802801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25128802801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2512880276 + ... + 2512880285.

It is an arithmetic number, because the mean of its divisors is an integer number (7538640843).

Almost surely, 2^25128802805 is an apocalyptic number.

It is an amenable number.

25128802805 is a deficient number, since it is larger than the sum of its proper divisors (5025760567).

25128802805 is an equidigital number, since it uses as much as digits as its factorization.

25128802805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5025760566.

The product of its (nonzero) digits is 102400, while the sum is 41.

The spelling of 25128802805 in words is "twenty-five billion, one hundred twenty-eight million, eight hundred two thousand, eight hundred five".