27755218081 has 4 divisors (see below), whose sum is σ = 27842774292. Its totient is φ = 27667661872.

The previous prime is 27755218063. The next prime is 27755218157. The reversal of 27755218081 is 18081255772.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16354317456 + 11400900625 = 127884^2 + 106775^2 .

It is a cyclic number.

It is not a de Polignac number, because 27755218081 - 2³¹ = 25607734433 is a prime.

It is a super-2 number, since 2×27755218081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27755219081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43777630 + ... + 43778263.

It is an arithmetic number, because the mean of its divisors is an integer number (6960693573).

Almost surely, 2^27755218081 is an apocalyptic number.

It is an amenable number.

27755218081 is a deficient number, since it is larger than the sum of its proper divisors (87556211).

27755218081 is an equidigital number, since it uses as much as digits as its factorization.

27755218081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87556210.

The product of its (nonzero) digits is 313600, while the sum is 46.

The spelling of 27755218081 in words is "twenty-seven billion, seven hundred fifty-five million, two hundred eighteen thousand, eighty-one".