81728916054660 has 432 divisors, whose sum is σ = 295588733993280. Its totient is φ = 18219863692800.

The previous prime is 81728916054659. The next prime is 81728916054671. The reversal of 81728916054660 is 6645061982718.

81728916054660 is a `hidden beast` number, since 8 + 1 + 7 + 2 + 8 + 9 + 160 + 5 + 466 + 0 = 666.

It is a super-2 number, since 2×81728916054660² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 59000271 + ... + 60369609.

It is an arithmetic number, because the mean of its divisors is an integer number (684233180540).

Almost surely, 2^{81728916054660} 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 81728916054660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147794366996640).

81728916054660 is an abundant number, since it is smaller than the sum of its proper divisors (213859817938620).

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

81728916054660 is a wasteful number, since it uses less digits than its factorization.

81728916054660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369536 (or 1369524 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 63.

The spelling of 81728916054660 in words is "eighty-one trillion, seven hundred twenty-eight billion, nine hundred sixteen million, fifty-four thousand, six hundred sixty".