81609047796 has 12 divisors (see below), whose sum is σ = 190421111552. Its totient is φ = 27203015928.

The previous prime is 81609047783. The next prime is 81609047797. The reversal of 81609047796 is 69774090618.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81609047797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3400376980 + ... + 3400377003.

Almost surely, 2^81609047796 is an apocalyptic number.

It is an amenable number.

81609047796 is an abundant number, since it is smaller than the sum of its proper divisors (108812063756).

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

81609047796 is a wasteful number, since it uses less digits than its factorization.

81609047796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6800753990 (or 6800753988 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 57.

The spelling of 81609047796 in words is "eighty-one billion, six hundred nine million, forty-seven thousand, seven hundred ninety-six".