181616806681 has 8 divisors (see below), whose sum is σ = 195621530720. Its totient is φ = 168056677152.

The previous prime is 181616806667. The next prime is 181616806687. The reversal of 181616806681 is 186608616181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 181616806681 - 2⁵ = 181616806649 is a prime.

It is a super-2 number, since 2×181616806681² (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 (181616806687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111147780 + ... + 111149413.

It is an arithmetic number, because the mean of its divisors is an integer number (24452691340).

Almost surely, 2^181616806681 is an apocalyptic number.

It is an amenable number.

181616806681 is a deficient number, since it is larger than the sum of its proper divisors (14004724039).

181616806681 is a wasteful number, since it uses less digits than its factorization.

181616806681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222297255.

The product of its (nonzero) digits is 663552, while the sum is 52.

The spelling of 181616806681 in words is "one hundred eighty-one billion, six hundred sixteen million, eight hundred six thousand, six hundred eighty-one".