181981816654986 has 80 divisors (see below), whose sum is σ = 407995640316000. Its totient is φ = 60627652237152.

The previous prime is 181981816654931. The next prime is 181981816654991. The reversal of 181981816654986 is 689456618189181.

181981816654986 is a `hidden beast` number, since 1 + 8 + 1 + 9 + 8 + 1 + 8 + 1 + 66 + 549 + 8 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3080075001 + ... + 3080134083.

It is an arithmetic number, because the mean of its divisors is an integer number (5099945503950).

Almost surely, 2^{181981816654986} is an apocalyptic number.

181981816654986 is an abundant number, since it is smaller than the sum of its proper divisors (226013823661014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

181981816654986 is a wasteful number, since it uses less digits than its factorization.

181981816654986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69105 (or 69096 counting only the distinct ones).

The product of its digits is 1433272320, while the sum is 81.

The spelling of 181981816654986 in words is "one hundred eighty-one trillion, nine hundred eighty-one billion, eight hundred sixteen million, six hundred fifty-four thousand, nine hundred eighty-six".