181728813 has 16 divisors (see below), whose sum is σ = 277401600. Its totient is φ = 103664496.

The previous prime is 181728803. The next prime is 181728829. The reversal of 181728813 is 318827181.

It is not a de Polignac number, because 181728813 - 2⁴ = 181728797 is a prime.

It is a super-2 number, since 2×181728813² = 66050722948777938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181728803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5356 + ... + 19802.

It is an arithmetic number, because the mean of its divisors is an integer number (17337600).

Almost surely, 2^181728813 is an apocalyptic number.

It is an amenable number.

181728813 is a deficient number, since it is larger than the sum of its proper divisors (95672787).

181728813 is a wasteful number, since it uses less digits than its factorization.

181728813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15056.

The product of its digits is 21504, while the sum is 39.

The square root of 181728813 is about 13480.6829574766. The cubic root of 181728813 is about 566.4235000893.

The spelling of 181728813 in words is "one hundred eighty-one million, seven hundred twenty-eight thousand, eight hundred thirteen".