81847043 has 2 divisors, whose sum is σ = 81847044. Its totient is φ = 81847042.

The previous prime is 81847039. The next prime is 81847049. The reversal of 81847043 is 34074818.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81847043 - 2² = 81847039 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 81846994 and 81847012.

It is not a weakly prime, because it can be changed into another prime (81847049) 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, 40923521 + 40923522.

It is an arithmetic number, because the mean of its divisors is an integer number (40923522).

Almost surely, 2^81847043 is an apocalyptic number.

81847043 is a deficient number, since it is larger than the sum of its proper divisors (1).

81847043 is an equidigital number, since it uses as much as digits as its factorization.

81847043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 81847043 is about 9046.9355585192. The cubic root of 81847043 is about 434.1778508267.

The spelling of 81847043 in words is "eighty-one million, eight hundred forty-seven thousand, forty-three".