81155185 has 8 divisors (see below), whose sum is σ = 97876800. Its totient is φ = 64597104.

The previous prime is 81155177. The next prime is 81155189. The reversal of 81155185 is 58155118.

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

It is a cyclic number.

It is not a de Polignac number, because 81155185 - 2³ = 81155177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81155185.

It is not an unprimeable number, because it can be changed into a prime (81155189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39787 + ... + 41776.

It is an arithmetic number, because the mean of its divisors is an integer number (12234600).

Almost surely, 2^81155185 is an apocalyptic number.

It is an amenable number.

81155185 is a deficient number, since it is larger than the sum of its proper divisors (16721615).

81155185 is a wasteful number, since it uses less digits than its factorization.

81155185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81767.

The product of its digits is 8000, while the sum is 34.

The square root of 81155185 is about 9008.6172634872. The cubic root of 81155185 is about 432.9510102504.

The spelling of 81155185 in words is "eighty-one million, one hundred fifty-five thousand, one hundred eighty-five".