81801698 has 8 divisors (see below), whose sum is σ = 133857360. Its totient is φ = 37182580.

The previous prime is 81801697. The next prime is 81801703. The reversal of 81801698 is 89610818.

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

It is not an unprimeable number, because it can be changed into a prime (81801697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1859108 + ... + 1859151.

It is an arithmetic number, because the mean of its divisors is an integer number (16732170).

Almost surely, 2^81801698 is an apocalyptic number.

81801698 is a deficient number, since it is larger than the sum of its proper divisors (52055662).

81801698 is a wasteful number, since it uses less digits than its factorization.

81801698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3718272.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 81801698 is about 9044.4291141011. The cubic root of 81801698 is about 434.0976547647.

The spelling of 81801698 in words is "eighty-one million, eight hundred one thousand, six hundred ninety-eight".