25709617881 has 6 divisors (see below), whose sum is σ = 37136114730. Its totient is φ = 17139745248.

The previous prime is 25709617873. The next prime is 25709617883. The reversal of 25709617881 is 18871690752.

25709617881 is a `hidden beast` number, since 2 + 570 + 9 + 61 + 7 + 8 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17071774281 + 8637843600 = 130659^2 + 92940^2 .

It is not a de Polignac number, because 25709617881 - 2³ = 25709617873 is a prime.

It is a super-2 number, since 2×25709617881² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25709617883) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1428312096 + ... + 1428312113.

It is an arithmetic number, because the mean of its divisors is an integer number (6189352455).

Almost surely, 2^25709617881 is an apocalyptic number.

It is an amenable number.

25709617881 is a deficient number, since it is larger than the sum of its proper divisors (11426496849).

25709617881 is a wasteful number, since it uses less digits than its factorization.

25709617881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2856624215 (or 2856624212 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 54.

The spelling of 25709617881 in words is "twenty-five billion, seven hundred nine million, six hundred seventeen thousand, eight hundred eighty-one".