81727832160 has 432 divisors, whose sum is σ = 309403680768. Its totient is φ = 19624550400.

The previous prime is 81727832149. The next prime is 81727832167. The reversal of 81727832160 is 6123872718.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81727832167) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9973665 + ... + 9981855.

It is an arithmetic number, because the mean of its divisors is an integer number (716212224).

Almost surely, 2^81727832160 is an apocalyptic number.

81727832160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81727832160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154701840384).

81727832160 is an abundant number, since it is smaller than the sum of its proper divisors (227675848608).

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

81727832160 is a wasteful number, since it uses less digits than its factorization.

81727832160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8279 (or 8255 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The spelling of 81727832160 in words is "eighty-one billion, seven hundred twenty-seven million, eight hundred thirty-two thousand, one hundred sixty".