81541064188 has 6 divisors (see below), whose sum is σ = 142696862336. Its totient is φ = 40770532092.

The previous prime is 81541064161. The next prime is 81541064207. The reversal of 81541064188 is 88146014518.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10192633020 + ... + 10192633027.

Almost surely, 2^81541064188 is an apocalyptic number.

It is an amenable number.

81541064188 is a deficient number, since it is larger than the sum of its proper divisors (61155798148).

81541064188 is a wasteful number, since it uses less digits than its factorization.

81541064188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20385266051 (or 20385266049 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 46.

The spelling of 81541064188 in words is "eighty-one billion, five hundred forty-one million, sixty-four thousand, one hundred eighty-eight".