81775554822 has 96 divisors (see below), whose sum is σ = 197719310880. Its totient is φ = 24253447680.

The previous prime is 81775554799. The next prime is 81775554853. The reversal of 81775554822 is 22845557718.

It is a happy number.

81775554822 is a `hidden beast` number, since 8 + 1 + 7 + 7 + 5 + 554 + 82 + 2 = 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, 4177197 + ... + 4196727.

It is an arithmetic number, because the mean of its divisors is an integer number (2059576155).

Almost surely, 2^81775554822 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81775554822, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98859655440).

81775554822 is an abundant number, since it is smaller than the sum of its proper divisors (115943756058).

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

81775554822 is a wasteful number, since it uses less digits than its factorization.

81775554822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20198 (or 20195 counting only the distinct ones).

The product of its digits is 6272000, while the sum is 54.

The spelling of 81775554822 in words is "eighty-one billion, seven hundred seventy-five million, five hundred fifty-four thousand, eight hundred twenty-two".