81920160 has 432 divisors, whose sum is σ = 345080736. Its totient is φ = 18289152.

The previous prime is 81920159. The next prime is 81920177. The reversal of 81920160 is 6102918.

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×81920160² = 13421825228851200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1905099 + ... + 1905141.

It is an arithmetic number, because the mean of its divisors is an integer number (798798).

Almost surely, 2^81920160 is an apocalyptic number.

81920160 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 81920160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172540368).

81920160 is an abundant number, since it is smaller than the sum of its proper divisors (263160576).

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

81920160 is a wasteful number, since it uses less digits than its factorization.

81920160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 81920160 is about 9050.9756380183. The cubic root of 81920160 is about 434.3071014068.

The spelling of 81920160 in words is "eighty-one million, nine hundred twenty thousand, one hundred sixty".