81800743069 has 2 divisors, whose sum is σ = 81800743070. Its totient is φ = 81800743068.

The previous prime is 81800743019. The next prime is 81800743133. The reversal of 81800743069 is 96034700818.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58988265625 + 22812477444 = 242875^2 + 151038^2 .

It is a cyclic number.

It is not a de Polignac number, because 81800743069 - 2¹³ = 81800734877 is a prime.

It is a super-2 number, since 2×81800743069² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81800743009) 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 as a sum of consecutive naturals, namely, 40900371534 + 40900371535.

It is an arithmetic number, because the mean of its divisors is an integer number (40900371535).

Almost surely, 2^81800743069 is an apocalyptic number.

It is an amenable number.

81800743069 is a deficient number, since it is larger than the sum of its proper divisors (1).

81800743069 is an equidigital number, since it uses as much as digits as its factorization.

81800743069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 81800743069 in words is "eighty-one billion, eight hundred million, seven hundred forty-three thousand, sixty-nine".