81546449 has 2 divisors, whose sum is σ = 81546450. Its totient is φ = 81546448.

The previous prime is 81546403. The next prime is 81546469. The reversal of 81546449 is 94464518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80874049 + 672400 = 8993^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 81546449 - 2⁸ = 81546193 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81546469) 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, 40773224 + 40773225.

It is an arithmetic number, because the mean of its divisors is an integer number (40773225).

Almost surely, 2^81546449 is an apocalyptic number.

It is an amenable number.

81546449 is a deficient number, since it is larger than the sum of its proper divisors (1).

81546449 is an equidigital number, since it uses as much as digits as its factorization.

81546449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 138240, while the sum is 41.

The square root of 81546449 is about 9030.3072483720. The cubic root of 81546449 is about 433.6456737635.

The spelling of 81546449 in words is "eighty-one million, five hundred forty-six thousand, four hundred forty-nine".