81726845587881 has 16 divisors (see below), whose sum is σ = 117382064384256. Its totient is φ = 50280287855616.

The previous prime is 81726845587879. The next prime is 81726845587921. The reversal of 81726845587881 is 18878554862718.

It is not a de Polignac number, because 81726845587881 - 2¹ = 81726845587879 is a prime.

It is a super-2 number, since 2×81726845587881² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81726845587797 and 81726845587806.

It is not an unprimeable number, because it can be changed into a prime (81726845587831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 273923640 + ... + 274221833.

It is an arithmetic number, because the mean of its divisors is an integer number (7336379024016).

Almost surely, 2^{81726845587881} is an apocalyptic number.

It is an amenable number.

81726845587881 is a deficient number, since it is larger than the sum of its proper divisors (35655218796375).

81726845587881 is a wasteful number, since it uses less digits than its factorization.

81726845587881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548149312.

The product of its digits is 1926758400, while the sum is 78.

The spelling of 81726845587881 in words is "eighty-one trillion, seven hundred twenty-six billion, eight hundred forty-five million, five hundred eighty-seven thousand, eight hundred eighty-one".