81928000 has 336 divisors, whose sum is σ = 271028160. Its totient is φ = 24192000.

The previous prime is 81927991. The next prime is 81928037. The reversal of 81928000 is 82918.

81928000 = 85³ + 86³ + ... + 139³.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 81928000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4311991 + ... + 4312009.

Almost surely, 2^81928000 is an apocalyptic number.

81928000 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 81928000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135514080).

81928000 is an abundant number, since it is smaller than the sum of its proper divisors (189100160).

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

81928000 is a wasteful number, since it uses less digits than its factorization.

81928000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 81928000 is about 9051.4087301370. The cubic root of 81928000 is about 434.3209557868.

The spelling of 81928000 in words is "eighty-one million, nine hundred twenty-eight thousand".