81181798 has 8 divisors (see below), whose sum is σ = 122157792. Its totient is φ = 40462536.

The previous prime is 81181787. The next prime is 81181801. The reversal of 81181798 is 89718118.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63390 + ... + 64657.

It is an arithmetic number, because the mean of its divisors is an integer number (15269724).

Almost surely, 2^81181798 is an apocalyptic number.

81181798 is a deficient number, since it is larger than the sum of its proper divisors (40975994).

81181798 is a wasteful number, since it uses less digits than its factorization.

81181798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128366.

The product of its digits is 32256, while the sum is 43.

The square root of 81181798 is about 9010.0942281421. The cubic root of 81181798 is about 432.9983305623.

The spelling of 81181798 in words is "eighty-one million, one hundred eighty-one thousand, seven hundred ninety-eight".