81136816755 has 128 divisors (see below), whose sum is σ = 141659062272. Its totient is φ = 39554431488.

The previous prime is 81136816753. The next prime is 81136816777. The reversal of 81136816755 is 55761863118.

It is not a de Polignac number, because 81136816755 - 2¹ = 81136816753 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 81136816698 and 81136816707.

It is not an unprimeable number, because it can be changed into a prime (81136816753) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 126184464 + ... + 126185106.

It is an arithmetic number, because the mean of its divisors is an integer number (1106711424).

Almost surely, 2^81136816755 is an apocalyptic number.

81136816755 is a deficient number, since it is larger than the sum of its proper divisors (60522245517).

81136816755 is a wasteful number, since it uses less digits than its factorization.

81136816755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897.

The product of its digits is 1209600, while the sum is 51.

The spelling of 81136816755 in words is "eighty-one billion, one hundred thirty-six million, eight hundred sixteen thousand, seven hundred fifty-five".