81844849 has 2 divisors, whose sum is σ = 81844850. Its totient is φ = 81844848.

The previous prime is 81844843. The next prime is 81844871. The reversal of 81844849 is 94844818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43652449 + 38192400 = 6607^2 + 6180^2 .

It is a cyclic number.

It is not a de Polignac number, because 81844849 - 2⁹ = 81844337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81844799 and 81844808.

It is not a weakly prime, because it can be changed into another prime (81844843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40922424 + 40922425.

It is an arithmetic number, because the mean of its divisors is an integer number (40922425).

Almost surely, 2^81844849 is an apocalyptic number.

It is an amenable number.

81844849 is a deficient number, since it is larger than the sum of its proper divisors (1).

81844849 is an equidigital number, since it uses as much as digits as its factorization.

81844849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 294912, while the sum is 46.

The square root of 81844849 is about 9046.8143011781. The cubic root of 81844849 is about 434.1739712537.

The spelling of 81844849 in words is "eighty-one million, eight hundred forty-four thousand, eight hundred forty-nine".