181654111681 has 9 divisors (see below), whose sum is σ = 211315396449. Its totient is φ = 155700967044.

The previous prime is 181654111679. The next prime is 181654111729. The reversal of 181654111681 is 186111456181.

The square root of 181654111681 is 426209.

It is a perfect power (a square), and thus also a powerful number.

181654111681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 181654111681 - 2¹ = 181654111679 is a prime.

It is a super-2 number, since 2×181654111681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181654111631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2953020 + ... + 3013906.

Almost surely, 2^181654111681 is an apocalyptic number.

181654111681 is the 426209-th square number.

181654111681 is the 213105-th centered octagonal number.

It is an amenable number.

181654111681 is a deficient number, since it is larger than the sum of its proper divisors (29661284768).

181654111681 is an frugal number, since it uses more digits than its factorization.

181654111681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121788 (or 60894 counting only the distinct ones).

The product of its digits is 46080, while the sum is 43.

The spelling of 181654111681 in words is "one hundred eighty-one billion, six hundred fifty-four million, one hundred eleven thousand, six hundred eighty-one".