81803447 has 8 divisors (see below), whose sum is σ = 89776512. Its totient is φ = 73919800.

The previous prime is 81803443. The next prime is 81803459. The reversal of 81803447 is 74430818.

It is a happy number.

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 81803447 - 2² = 81803443 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81803443) 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, 20429 + ... + 24102.

It is an arithmetic number, because the mean of its divisors is an integer number (11222064).

Almost surely, 2^81803447 is an apocalyptic number.

81803447 is a deficient number, since it is larger than the sum of its proper divisors (7973065).

81803447 is a wasteful number, since it uses less digits than its factorization.

81803447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44709.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 81803447 is about 9044.5258029374. The cubic root of 81803447 is about 434.1007485530.

The spelling of 81803447 in words is "eighty-one million, eight hundred three thousand, four hundred forty-seven".