181642 has 4 divisors (see below), whose sum is σ = 272466. Its totient is φ = 90820.

The previous prime is 181639. The next prime is 181667. The reversal of 181642 is 246181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 145161 + 36481 = 381^2 + 191^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45409 + ... + 45412.

2¹⁸¹⁶⁴² is an apocalyptic number.

181642 is a deficient number, since it is larger than the sum of its proper divisors (90824).

181642 is an equidigital number, since it uses as much as digits as its factorization.

181642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90823.

The product of its digits is 384, while the sum is 22.

The square root of 181642 is about 426.1947911460. The cubic root of 181642 is about 56.6333291031.

The spelling of 181642 in words is "one hundred eighty-one thousand, six hundred forty-two".