81771682155017 has 16 divisors (see below), whose sum is σ = 85349032624128. Its totient is φ = 78196172780880.

The previous prime is 81771682155001. The next prime is 81771682155043. The reversal of 81771682155017 is 71055128617718.

It is a cyclic number.

It is not a de Polignac number, because 81771682155017 - 2⁴ = 81771682155001 is a prime.

It is a super-2 number, since 2×81771682155017² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81771682157017) 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, 1870712792 + ... + 1870756502.

It is an arithmetic number, because the mean of its divisors is an integer number (5334314539008).

Almost surely, 2^{81771682155017} is an apocalyptic number.

It is an amenable number.

81771682155017 is a deficient number, since it is larger than the sum of its proper divisors (3577350469111).

81771682155017 is a wasteful number, since it uses less digits than its factorization.

81771682155017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62900.

The product of its (nonzero) digits is 6585600, while the sum is 59.

The spelling of 81771682155017 in words is "eighty-one trillion, seven hundred seventy-one billion, six hundred eighty-two million, one hundred fifty-five thousand, seventeen".