81765803 has 16 divisors (see below), whose sum is σ = 96797376. Its totient is φ = 67616640.

The previous prime is 81765791. The next prime is 81765811. The reversal of 81765803 is 30856718.

It is not a de Polignac number, because 81765803 - 2¹⁰ = 81764779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81765823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20825 + ... + 24437.

It is an arithmetic number, because the mean of its divisors is an integer number (6049836).

Almost surely, 2^81765803 is an apocalyptic number.

81765803 is a deficient number, since it is larger than the sum of its proper divisors (15031573).

81765803 is a wasteful number, since it uses less digits than its factorization.

81765803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3734.

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 81765803 is about 9042.4445256800. Note that the first 3 decimals coincide. The cubic root of 81765803 is about 434.0341507243.

The spelling of 81765803 in words is "eighty-one million, seven hundred sixty-five thousand, eight hundred three".