81729343 has 2 divisors, whose sum is σ = 81729344. Its totient is φ = 81729342.

The previous prime is 81729313. The next prime is 81729377. The reversal of 81729343 is 34392718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81729343 - 2⁵ = 81729311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81729313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40864671 + 40864672.

It is an arithmetic number, because the mean of its divisors is an integer number (40864672).

Almost surely, 2^81729343 is an apocalyptic number.

81729343 is a deficient number, since it is larger than the sum of its proper divisors (1).

81729343 is an equidigital number, since it uses as much as digits as its factorization.

81729343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 81729343 is about 9040.4282531305. The cubic root of 81729343 is about 433.9696280784.

The spelling of 81729343 in words is "eighty-one million, seven hundred twenty-nine thousand, three hundred forty-three".