81803317 has 2 divisors, whose sum is σ = 81803318. Its totient is φ = 81803316.

The previous prime is 81803311. The next prime is 81803333. The reversal of 81803317 is 71330818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69122596 + 12680721 = 8314^2 + 3561^2 .

It is a cyclic number.

It is not a de Polignac number, because 81803317 - 2²³ = 73414709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81803311) 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 as a sum of consecutive naturals, namely, 40901658 + 40901659.

It is an arithmetic number, because the mean of its divisors is an integer number (40901659).

Almost surely, 2^81803317 is an apocalyptic number.

It is an amenable number.

81803317 is a deficient number, since it is larger than the sum of its proper divisors (1).

81803317 is an equidigital number, since it uses as much as digits as its factorization.

81803317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 81803317 is about 9044.5186162670. The cubic root of 81803317 is about 434.1005185988.

The spelling of 81803317 in words is "eighty-one million, eight hundred three thousand, three hundred seventeen".