181806772085 has 16 divisors (see below), whose sum is σ = 231012565056. Its totient is φ = 136883275008.

The previous prime is 181806772057. The next prime is 181806772117. The reversal of 181806772085 is 580277608181.

It is a cyclic number.

It is not a de Polignac number, because 181806772085 - 2⁸ = 181806771829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2469782 + ... + 2542328.

It is an arithmetic number, because the mean of its divisors is an integer number (14438285316).

Almost surely, 2^181806772085 is an apocalyptic number.

It is an amenable number.

181806772085 is a deficient number, since it is larger than the sum of its proper divisors (49205792971).

181806772085 is a wasteful number, since it uses less digits than its factorization.

181806772085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102052.

The product of its (nonzero) digits is 1505280, while the sum is 53.

The spelling of 181806772085 in words is "one hundred eighty-one billion, eight hundred six million, seven hundred seventy-two thousand, eighty-five".