81730185 has 8 divisors (see below), whose sum is σ = 130768320. Its totient is φ = 43589424.

The previous prime is 81730171. The next prime is 81730219. The reversal of 81730185 is 58103718.

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

It is not a de Polignac number, because 81730185 - 2¹¹ = 81728137 is a prime.

It is a Curzon number.

It is a plaindrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2724325 + ... + 2724354.

It is an arithmetic number, because the mean of its divisors is an integer number (16346040).

Almost surely, 2^81730185 is an apocalyptic number.

It is an amenable number.

81730185 is a deficient number, since it is larger than the sum of its proper divisors (49038135).

81730185 is a wasteful number, since it uses less digits than its factorization.

81730185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5448687.

The product of its (nonzero) digits is 6720, while the sum is 33.

The square root of 81730185 is about 9040.4748216009. The cubic root of 81730185 is about 433.9711183680.

The spelling of 81730185 in words is "eighty-one million, seven hundred thirty thousand, one hundred eighty-five".