81603194784 has 96 divisors (see below), whose sum is σ = 219596832000. Its totient is φ = 26517811200.

The previous prime is 81603194737. The next prime is 81603194809. The reversal of 81603194784 is 48749130618.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5822217 + ... + 5836215.

It is an arithmetic number, because the mean of its divisors is an integer number (2287467000).

Almost surely, 2^81603194784 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 81603194784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109798416000).

81603194784 is an abundant number, since it is smaller than the sum of its proper divisors (137993637216).

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

81603194784 is a wasteful number, since it uses less digits than its factorization.

81603194784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15534 (or 15526 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 51.

The spelling of 81603194784 in words is "eighty-one billion, six hundred three million, one hundred ninety-four thousand, seven hundred eighty-four".