25809165641 has 16 divisors (see below), whose sum is σ = 32119267200. Its totient is φ = 20235132288.

The previous prime is 25809165623. The next prime is 25809165643. The reversal of 25809165641 is 14656190852.

It is not a de Polignac number, because 25809165641 - 2³⁴ = 8629296457 is a prime.

It is a super-2 number, since 2×25809165641² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25809165643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3341900 + ... + 3349613.

It is an arithmetic number, because the mean of its divisors is an integer number (2007454200).

Almost surely, 2^25809165641 is an apocalyptic number.

It is an amenable number.

25809165641 is a deficient number, since it is larger than the sum of its proper divisors (6310101559).

25809165641 is a wasteful number, since it uses less digits than its factorization.

25809165641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6691568.

The product of its (nonzero) digits is 518400, while the sum is 47.

The spelling of 25809165641 in words is "twenty-five billion, eight hundred nine million, one hundred sixty-five thousand, six hundred forty-one".