81108187545 has 32 divisors (see below), whose sum is σ = 161795036160. Its totient is φ = 33707298240.

The previous prime is 81108187513. The next prime is 81108187547. The reversal of 81108187545 is 54578180118.

It is a happy number.

It is not a de Polignac number, because 81108187545 - 2⁵ = 81108187513 is a prime.

It is a Smith number, since the sum of its digits (48) 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 = 81108187494 and 81108187503.

It is not an unprimeable number, because it can be changed into a prime (81108187547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35110615 + ... + 35112924.

It is an arithmetic number, because the mean of its divisors is an integer number (5056094880).

Almost surely, 2^81108187545 is an apocalyptic number.

It is an amenable number.

81108187545 is a deficient number, since it is larger than the sum of its proper divisors (80686848615).

81108187545 is a wasteful number, since it uses less digits than its factorization.

81108187545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70223565.

The product of its (nonzero) digits is 358400, while the sum is 48.

The spelling of 81108187545 in words is "eighty-one billion, one hundred eight million, one hundred eighty-seven thousand, five hundred forty-five".