181664673 has 8 divisors (see below), whose sum is σ = 245138208. Its totient is φ = 119650464.

The previous prime is 181664663. The next prime is 181664677. The reversal of 181664673 is 376466181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 181664673 - 2⁴ = 181664657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (181664677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 364540 + ... + 365037.

It is an arithmetic number, because the mean of its divisors is an integer number (30642276).

Almost surely, 2^181664673 is an apocalyptic number.

It is an amenable number.

181664673 is a deficient number, since it is larger than the sum of its proper divisors (63473535).

181664673 is an equidigital number, since it uses as much as digits as its factorization.

181664673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729663.

The product of its digits is 145152, while the sum is 42.

The square root of 181664673 is about 13478.3037879401. The cubic root of 181664673 is about 566.3568537538.

The spelling of 181664673 in words is "one hundred eighty-one million, six hundred sixty-four thousand, six hundred seventy-three".