81654835181 has 2 divisors, whose sum is σ = 81654835182. Its totient is φ = 81654835180.

The previous prime is 81654835133. The next prime is 81654835187. The reversal of 81654835181 is 18153845618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51494955625 + 30159879556 = 226925^2 + 173666^2 .

It is a cyclic number.

It is not a de Polignac number, because 81654835181 - 2⁶ = 81654835117 is a prime.

It is a super-3 number, since 3×81654835181³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81654835187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40827417590 + 40827417591.

It is an arithmetic number, because the mean of its divisors is an integer number (40827417591).

Almost surely, 2^81654835181 is an apocalyptic number.

It is an amenable number.

81654835181 is a deficient number, since it is larger than the sum of its proper divisors (1).

81654835181 is an equidigital number, since it uses as much as digits as its factorization.

81654835181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 921600, while the sum is 50.

The spelling of 81654835181 in words is "eighty-one billion, six hundred fifty-four million, eight hundred thirty-five thousand, one hundred eighty-one".