81841695289601 has 24 divisors (see below), whose sum is σ = 90034756515000. Its totient is φ = 74350723779072.

The previous prime is 81841695289583. The next prime is 81841695289663. The reversal of 81841695289601 is 10698259614818.

It is a Cunningham number, because it is equal to 9046640²+1.

It can be written as a sum of positive squares in 12 ways, for example, as 24798417999601 + 57043277290000 = 4979801^2 + 7552700^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81841695289601 is a prime.

It is a super-2 number, since 2×81841695289601² (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 (81841695289681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12164156 + ... + 17653613.

It is an arithmetic number, because the mean of its divisors is an integer number (3751448188125).

Almost surely, 2^{81841695289601} is an apocalyptic number.

It is an amenable number.

81841695289601 is a deficient number, since it is larger than the sum of its proper divisors (8193061225399).

81841695289601 is a wasteful number, since it uses less digits than its factorization.

81841695289601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29818053 (or 29818040 counting only the distinct ones).

The product of its (nonzero) digits is 59719680, while the sum is 68.

The spelling of 81841695289601 in words is "eighty-one trillion, eight hundred forty-one billion, six hundred ninety-five million, two hundred eighty-nine thousand, six hundred one".