181312 has 14 divisors (see below), whose sum is σ = 359918. Its totient is φ = 90624.

The previous prime is 181303. The next prime is 181361. The reversal of 181312 is 213181.

It can be written as a sum of positive squares in only one way, i.e., 147456 + 33856 = 384^2 + 184^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a nialpdrome in base 8.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1353 + ... + 1480.

2¹⁸¹³¹² is an apocalyptic number.

It is an amenable number.

181312 is a deficient number, since it is larger than the sum of its proper divisors (178606).

181312 is an equidigital number, since it uses as much as digits as its factorization.

181312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2845 (or 2835 counting only the distinct ones).

The product of its digits is 48, while the sum is 16.

The square root of 181312 is about 425.8074682295. The cubic root of 181312 is about 56.5990119153.

Adding to 181312 its reverse (213181), we get a palindrome (394493).

The spelling of 181312 in words is "one hundred eighty-one thousand, three hundred twelve".