81600 has 84 divisors (see below), whose sum is σ = 283464. Its totient is φ = 20480.

The previous prime is 81569. The next prime is 81611. The reversal of 81600 is 618.

81600 = T₁₅ + T₁₆ + ... + T₇₈.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 81600.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81600.

It is an unprimeable number.

81600 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4792 + ... + 4808.

2⁸¹⁶⁰⁰ is an apocalyptic number.

81600 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 81600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141732).

81600 is an abundant number, since it is smaller than the sum of its proper divisors (201864).

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

81600 is a wasteful number, since it uses less digits than its factorization.

81600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 81600 is about 285.6571371417. The cubic root of 81600 is about 43.3740577050.

The spelling of 81600 in words is "eighty-one thousand, six hundred".