181584540 has 108 divisors (see below), whose sum is σ = 576097704. Its totient is φ = 46292928.

The previous prime is 181584527. The next prime is 181584541. The reversal of 181584540 is 45485181.

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

It is a junction number, because it is equal to n+sod(n) for n = 181584495 and 181584504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181584541) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 94267 + ... + 96173.

It is an arithmetic number, because the mean of its divisors is an integer number (5334238).

Almost surely, 2^181584540 is an apocalyptic number.

181584540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181584540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (288048852).

181584540 is an abundant number, since it is smaller than the sum of its proper divisors (394513164).

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

181584540 is a wasteful number, since it uses less digits than its factorization.

181584540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1968 (or 1940 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 36.

The square root of 181584540 is about 13475.3307937134. The cubic root of 181584540 is about 566.2735674298.

The spelling of 181584540 in words is "one hundred eighty-one million, five hundred eighty-four thousand, five hundred forty".