81126216189 has 12 divisors (see below), whose sum is σ = 117188169696. Its totient is φ = 54081440712.

The previous prime is 81126216187. The next prime is 81126216203. The reversal of 81126216189 is 98161262118.

It is a happy number.

81126216189 is a `hidden beast` number, since 8 + 1 + 1 + 2 + 6 + 21 + 618 + 9 = 666.

It is not a de Polignac number, because 81126216189 - 2¹ = 81126216187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81126216187) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25947 + ... + 403640.

It is an arithmetic number, because the mean of its divisors is an integer number (9765680808).

Almost surely, 2^81126216189 is an apocalyptic number.

It is an amenable number.

81126216189 is a deficient number, since it is larger than the sum of its proper divisors (36061953507).

81126216189 is a wasteful number, since it uses less digits than its factorization.

81126216189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450576 (or 450573 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The spelling of 81126216189 in words is "eighty-one billion, one hundred twenty-six million, two hundred sixteen thousand, one hundred eighty-nine".