81065600 has 288 divisors, whose sum is σ = 259536960. Its totient is φ = 24729600.

The previous prime is 81065549. The next prime is 81065623. The reversal of 81065600 is 656018.

It is a self number, because there is not a number n which added to its sum of digits gives 81065600.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1724777 + ... + 1724823.

It is an arithmetic number, because the mean of its divisors is an integer number (901170).

Almost surely, 2^81065600 is an apocalyptic number.

81065600 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 81065600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129768480).

81065600 is an abundant number, since it is smaller than the sum of its proper divisors (178471360).

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

81065600 is a wasteful number, since it uses less digits than its factorization.

81065600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 81065600 is about 9003.6437068556. The cubic root of 81065600 is about 432.7916439837.

The spelling of 81065600 in words is "eighty-one million, sixty-five thousand, six hundred".