81769243 has 2 divisors, whose sum is σ = 81769244. Its totient is φ = 81769242.

The previous prime is 81769153. The next prime is 81769249. The reversal of 81769243 is 34296718.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81769243 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81769196 and 81769205.

It is not a weakly prime, because it can be changed into another prime (81769249) 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, 40884621 + 40884622.

It is an arithmetic number, because the mean of its divisors is an integer number (40884622).

Almost surely, 2^81769243 is an apocalyptic number.

81769243 is a deficient number, since it is larger than the sum of its proper divisors (1).

81769243 is an equidigital number, since it uses as much as digits as its factorization.

81769243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 81769243 is about 9042.6347377299. The cubic root of 81769243 is about 434.0402374439.

The spelling of 81769243 in words is "eighty-one million, seven hundred sixty-nine thousand, two hundred forty-three".