81904798 has 8 divisors (see below), whose sum is σ = 125853840. Its totient is φ = 39953520.

The previous prime is 81904789. The next prime is 81904813. The reversal of 81904798 is 89740918.

It is a happy number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 499338 + ... + 499501.

It is an arithmetic number, because the mean of its divisors is an integer number (15731730).

Almost surely, 2^81904798 is an apocalyptic number.

81904798 is a deficient number, since it is larger than the sum of its proper divisors (43949042).

81904798 is a wasteful number, since it uses less digits than its factorization.

81904798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998882.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 81904798 is about 9050.1269604354. The cubic root of 81904798 is about 434.2799520345.

The spelling of 81904798 in words is "eighty-one million, nine hundred four thousand, seven hundred ninety-eight".