81178343 has 2 divisors, whose sum is σ = 81178344. Its totient is φ = 81178342.

The previous prime is 81178327. The next prime is 81178379. The reversal of 81178343 is 34387118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81178343 - 2⁴ = 81178327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81178303) 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, 40589171 + 40589172.

It is an arithmetic number, because the mean of its divisors is an integer number (40589172).

Almost surely, 2^81178343 is an apocalyptic number.

81178343 is a deficient number, since it is larger than the sum of its proper divisors (1).

81178343 is an equidigital number, since it uses as much as digits as its factorization.

81178343 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 35.

The square root of 81178343 is about 9009.9024966977. The cubic root of 81178343 is about 432.9921878452.

The spelling of 81178343 in words is "eighty-one million, one hundred seventy-eight thousand, three hundred forty-three".