25809377645 has 12 divisors (see below), whose sum is σ = 32900260404. Its totient is φ = 19432942080.

The previous prime is 25809377621. The next prime is 25809377653. The reversal of 25809377645 is 54677390852.

It can be written as a sum of positive squares in 6 ways, for example, as 144696841 + 25664680804 = 12029^2 + 160202^2 .

It is not a de Polignac number, because 25809377645 - 2²⁰ = 25808329069 is a prime.

It is a super-3 number, since 3×25809377645³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8929136 + ... + 8932025.

It is an arithmetic number, because the mean of its divisors is an integer number (2741688367).

Almost surely, 2^25809377645 is an apocalyptic number.

It is an amenable number.

25809377645 is a deficient number, since it is larger than the sum of its proper divisors (7090882759).

25809377645 is a wasteful number, since it uses less digits than its factorization.

25809377645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17861200 (or 17861183 counting only the distinct ones).

The product of its (nonzero) digits is 12700800, while the sum is 56.

The spelling of 25809377645 in words is "twenty-five billion, eight hundred nine million, three hundred seventy-seven thousand, six hundred forty-five".