81711675144 has 192 divisors, whose sum is σ = 255469593600. Its totient is φ = 23350588800.

The previous prime is 81711675131. The next prime is 81711675163. The reversal of 81711675144 is 44157611718.

81711675144 is a `hidden beast` number, since 8 + 1 + 71 + 1 + 67 + 514 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81711675144.

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, 1261747 + ... + 1324925.

It is an arithmetic number, because the mean of its divisors is an integer number (1330570800).

Almost surely, 2^81711675144 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 81711675144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127734796800).

81711675144 is an abundant number, since it is smaller than the sum of its proper divisors (173757918456).

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

81711675144 is a wasteful number, since it uses less digits than its factorization.

81711675144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63296 (or 63289 counting only the distinct ones).

The product of its digits is 188160, while the sum is 45.

The spelling of 81711675144 in words is "eighty-one billion, seven hundred eleven million, six hundred seventy-five thousand, one hundred forty-four".