81027126575137 has 4 divisors (see below), whose sum is σ = 81380956822420. Its totient is φ = 80673296327856.

The previous prime is 81027126575111. The next prime is 81027126575149. The reversal of 81027126575137 is 73157562172018.

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 51339001935376 + 29688124639761 = 7165124^2 + 5448681^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81027126575137 is a prime.

It is a super-3 number, since 3×81027126575137³ (a number of 43 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81027126575167) 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 3 ways as a sum of consecutive naturals, for example, 176915123298 + ... + 176915123755.

It is an arithmetic number, because the mean of its divisors is an integer number (20345239205605).

Almost surely, 2^{81027126575137} is an apocalyptic number.

It is an amenable number.

81027126575137 is a deficient number, since it is larger than the sum of its proper divisors (353830247283).

81027126575137 is a wasteful number, since it uses less digits than its factorization.

81027126575137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353830247282.

The product of its (nonzero) digits is 4939200, while the sum is 55.

The spelling of 81027126575137 in words is "eighty-one trillion, twenty-seven billion, one hundred twenty-six million, five hundred seventy-five thousand, one hundred thirty-seven".