25581395606 has 16 divisors (see below), whose sum is σ = 41357633184. Its totient is φ = 11797129344.

The previous prime is 25581395549. The next prime is 25581395633. The reversal of 25581395606 is 60659318552.

It is a super-2 number, since 2×25581395606² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 370451 + ... + 434046.

It is an arithmetic number, because the mean of its divisors is an integer number (2584852074).

Almost surely, 2^25581395606 is an apocalyptic number.

25581395606 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

25581395606 is a deficient number, since it is larger than the sum of its proper divisors (15776237578).

25581395606 is a wasteful number, since it uses less digits than its factorization.

25581395606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805735.

The product of its (nonzero) digits is 1944000, while the sum is 50.

The spelling of 25581395606 in words is "twenty-five billion, five hundred eighty-one million, three hundred ninety-five thousand, six hundred six".