27717381681 has 16 divisors (see below), whose sum is σ = 40493806848. Its totient is φ = 16724406800.

The previous prime is 27717381661. The next prime is 27717381683. The reversal of 27717381681 is 18618371772.

It is a cyclic number.

It is not a de Polignac number, because 27717381681 - 2⁶ = 27717381617 is a prime.

It is a super-2 number, since 2×27717381681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (27717381683) 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 15 ways as a sum of consecutive naturals, for example, 1842555 + ... + 1857536.

It is an arithmetic number, because the mean of its divisors is an integer number (2530862928).

Almost surely, 2^27717381681 is an apocalyptic number.

It is an amenable number.

27717381681 is a deficient number, since it is larger than the sum of its proper divisors (12776425167).

27717381681 is a wasteful number, since it uses less digits than its factorization.

27717381681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700332.

The product of its digits is 790272, while the sum is 51.

Subtracting from 27717381681 its reverse (18618371772), we obtain a palindrome (9099009909).

The spelling of 27717381681 in words is "twenty-seven billion, seven hundred seventeen million, three hundred eighty-one thousand, six hundred eighty-one".