81675216 has 120 divisors (see below), whose sum is σ = 270996544. Its totient is φ = 23328000.

The previous prime is 81675199. The next prime is 81675221. The reversal of 81675216 is 61257618.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25716 + ... + 28716.

Almost surely, 2^81675216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81675216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135498272).

81675216 is an abundant number, since it is smaller than the sum of its proper divisors (189321328).

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

81675216 is a wasteful number, since it uses less digits than its factorization.

81675216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3031 (or 3013 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 81675216 is about 9037.4341491377. The cubic root of 81675216 is about 433.8738050419.

The spelling of 81675216 in words is "eighty-one million, six hundred seventy-five thousand, two hundred sixteen".