25128802809 has 48 divisors (see below), whose sum is σ = 40722739200. Its totient is φ = 14800151520.

The previous prime is 25128802801. The next prime is 25128802823. The reversal of 25128802809 is 90820882152.

It is not a de Polignac number, because 25128802809 - 2³ = 25128802801 is a prime.

It is a super-2 number, since 2×25128802809² (a number of 22 digits) contains 22 as substring.

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 47 ways as a sum of consecutive naturals, for example, 832312 + ... + 861974.

It is an arithmetic number, because the mean of its divisors is an integer number (848390400).

Almost surely, 2^25128802809 is an apocalyptic number.

It is an amenable number.

25128802809 is a deficient number, since it is larger than the sum of its proper divisors (15593936391).

25128802809 is a wasteful number, since it uses less digits than its factorization.

25128802809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29922 (or 29919 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The spelling of 25128802809 in words is "twenty-five billion, one hundred twenty-eight million, eight hundred two thousand, eight hundred nine".