81197184 has 128 divisors (see below), whose sum is σ = 235008000. Its totient is φ = 24744960.

The previous prime is 81197159. The next prime is 81197189. The reversal of 81197184 is 48179118.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (81197189) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225997 + ... + 226355.

It is an arithmetic number, because the mean of its divisors is an integer number (1836000).

Almost surely, 2^81197184 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 81197184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117504000).

81197184 is an abundant number, since it is smaller than the sum of its proper divisors (153810816).

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

81197184 is a wasteful number, since it uses less digits than its factorization.

81197184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426 (or 414 counting only the distinct ones).

The product of its digits is 16128, while the sum is 39.

The square root of 81197184 is about 9010.9480078402. The cubic root of 81197184 is about 433.0256835390.

The spelling of 81197184 in words is "eighty-one million, one hundred ninety-seven thousand, one hundred eighty-four".