81133184 has 64 divisors (see below), whose sum is σ = 182498400. Its totient is φ = 35589120.

The previous prime is 81133183. The next prime is 81133187. The reversal of 81133184 is 48133118.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (81133183) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39839 + ... + 41825.

Almost surely, 2^81133184 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 81133184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91249200).

81133184 is an abundant number, since it is smaller than the sum of its proper divisors (101365216).

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

81133184 is a wasteful number, since it uses less digits than its factorization.

81133184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041 (or 2029 counting only the distinct ones).

The product of its digits is 2304, while the sum is 29.

The square root of 81133184 is about 9007.3960721176. The cubic root of 81133184 is about 432.9118826783.

The spelling of 81133184 in words is "eighty-one million, one hundred thirty-three thousand, one hundred eighty-four".