81194328989244 has 144 divisors (see below), whose sum is σ = 224096453642880. Its totient is φ = 25634425596480.

The previous prime is 81194328989231. The next prime is 81194328989261. The reversal of 81194328989244 is 44298982349118.

81194328989244 is a `hidden beast` number, since 8 + 1 + 1 + 94 + 328 + 98 + 92 + 44 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 80257879 + ... + 81263249.

It is an arithmetic number, because the mean of its divisors is an integer number (1556225372520).

Almost surely, 2^{81194328989244} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81194328989244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112048226821440).

81194328989244 is an abundant number, since it is smaller than the sum of its proper divisors (142902124653636).

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

81194328989244 is a wasteful number, since it uses less digits than its factorization.

81194328989244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1009782 (or 1009768 counting only the distinct ones).

The product of its digits is 286654464, while the sum is 72.

The spelling of 81194328989244 in words is "eighty-one trillion, one hundred ninety-four billion, three hundred twenty-eight million, nine hundred eighty-nine thousand, two hundred forty-four".