181664 has 24 divisors (see below), whose sum is σ = 409248. Its totient is φ = 77760.

The previous prime is 181639. The next prime is 181667. The reversal of 181664 is 466181.

It is not an unprimeable number, because it can be changed into a prime (181667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182 + ... + 629.

It is an arithmetic number, because the mean of its divisors is an integer number (17052).

2¹⁸¹⁶⁶⁴ is an apocalyptic number.

181664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

181664 is an abundant number, since it is smaller than the sum of its proper divisors (227584).

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

181664 is an equidigital number, since it uses as much as digits as its factorization.

181664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828 (or 820 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 181664 is about 426.2206001591. The cubic root of 181664 is about 56.6356154372.

The spelling of 181664 in words is "one hundred eighty-one thousand, six hundred sixty-four".