25809386409 has 9 divisors (see below), whose sum is σ = 37280920989. Its totient is φ = 17205936300.

The previous prime is 25809386363. The next prime is 25809386413. The reversal of 25809386409 is 90468390852.

The square root of 25809386409 is 160653.

It is a perfect power (a square), and thus also a powerful number.

25809386409 is a `hidden beast` number, since 258 + 0 + 9 + 386 + 4 + 0 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 25809386409 - 2²¹ = 25807289257 is a prime.

It is a super-2 number, since 2×25809386409² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25809386479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 455184 + ... + 508734.

Almost surely, 2^25809386409 is an apocalyptic number.

25809386409 is the 160653-rd square number.

25809386409 is the 80327-th centered octagonal number.

It is an amenable number.

25809386409 is a deficient number, since it is larger than the sum of its proper divisors (11471534580).

25809386409 is an frugal number, since it uses more digits than its factorization.

25809386409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107108 (or 53554 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 25809386409 in words is "twenty-five billion, eight hundred nine million, three hundred eighty-six thousand, four hundred nine".