27955155155981 has 2 divisors, whose sum is σ = 27955155155982. Its totient is φ = 27955155155980.

The previous prime is 27955155155971. The next prime is 27955155155989. The reversal of 27955155155981 is 18955155155972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25970744822500 + 1984410333481 = 5096150^2 + 1408691^2 .

It is a cyclic number.

It is not a de Polignac number, because 27955155155981 - 2³⁴ = 27937975286797 is a prime.

It is a super-2 number, since 2×27955155155981² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27955155155989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13977577577990 + 13977577577991.

It is an arithmetic number, because the mean of its divisors is an integer number (13977577577991).

Almost surely, 2^{27955155155981} is an apocalyptic number.

It is an amenable number.

27955155155981 is a deficient number, since it is larger than the sum of its proper divisors (1).

27955155155981 is an equidigital number, since it uses as much as digits as its factorization.

27955155155981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141750000, while the sum is 68.

Subtracting from 27955155155981 its reverse (18955155155972), we obtain a palindrome (9000000000009).

The spelling of 27955155155981 in words is "twenty-seven trillion, nine hundred fifty-five billion, one hundred fifty-five million, one hundred fifty-five thousand, nine hundred eighty-one".