181131984 has 160 divisors (see below), whose sum is σ = 579962880. Its totient is φ = 53654400.

The previous prime is 181131967. The next prime is 181132009. The reversal of 181131984 is 489131181.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 222939 + ... + 223749.

It is an arithmetic number, because the mean of its divisors is an integer number (3624768).

Almost surely, 2^181131984 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 181131984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289981440).

181131984 is an abundant number, since it is smaller than the sum of its proper divisors (398830896).

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

181131984 is a wasteful number, since it uses less digits than its factorization.

181131984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 874 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 181131984 is about 13458.5282999294. The cubic root of 181131984 is about 565.8027423007.

The spelling of 181131984 in words is "one hundred eighty-one million, one hundred thirty-one thousand, nine hundred eighty-four".