81516 has 12 divisors (see below), whose sum is σ = 190232. Its totient is φ = 27168.

The previous prime is 81509. The next prime is 81517. The reversal of 81516 is 61518.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 81492 and 81501.

It is not an unprimeable number, because it can be changed into a prime (81517) by changing a digit.

81516 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 3 ways as a sum of consecutive naturals, for example, 3385 + ... + 3408.

2⁸¹⁵¹⁶ is an apocalyptic number.

It is an amenable number.

81516 is an abundant number, since it is smaller than the sum of its proper divisors (108716).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95116).

81516 is a wasteful number, since it uses less digits than its factorization.

81516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6800 (or 6798 counting only the distinct ones).

The product of its digits is 240, while the sum is 21.

The square root of 81516 is about 285.5100698750. The cubic root of 81516 is about 43.3591693400.

The spelling of 81516 in words is "eighty-one thousand, five hundred sixteen".