27725361681 has 4 divisors (see below), whose sum is σ = 36967148912. Its totient is φ = 18483574452.

The previous prime is 27725361667. The next prime is 27725361683. The reversal of 27725361681 is 18616352772.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 27725361681 - 2⁵ = 27725361649 is a prime.

It is a super-2 number, since 2×27725361681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27725361681.

It is not an unprimeable number, because it can be changed into a prime (27725361683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4620893611 + ... + 4620893616.

It is an arithmetic number, because the mean of its divisors is an integer number (9241787228).

Almost surely, 2^27725361681 is an apocalyptic number.

It is an amenable number.

27725361681 is a deficient number, since it is larger than the sum of its proper divisors (9241787231).

27725361681 is an equidigital number, since it uses as much as digits as its factorization.

27725361681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9241787230.

The product of its digits is 846720, while the sum is 48.

The spelling of 27725361681 in words is "twenty-seven billion, seven hundred twenty-five million, three hundred sixty-one thousand, six hundred eighty-one".