81831449 has 16 divisors (see below), whose sum is σ = 96284160. Its totient is φ = 68087040.

The previous prime is 81831433. The next prime is 81831469. The reversal of 81831449 is 94413818.

It is not a de Polignac number, because 81831449 - 2⁴ = 81831433 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81831469) 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 in 15 ways as a sum of consecutive naturals, for example, 67997 + ... + 69189.

It is an arithmetic number, because the mean of its divisors is an integer number (6017760).

Almost surely, 2^81831449 is an apocalyptic number.

It is an amenable number.

81831449 is a deficient number, since it is larger than the sum of its proper divisors (14452711).

81831449 is a wasteful number, since it uses less digits than its factorization.

81831449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1480.

The product of its digits is 27648, while the sum is 38.

The square root of 81831449 is about 9046.0736786741. The cubic root of 81831449 is about 434.1502750007.

The spelling of 81831449 in words is "eighty-one million, eight hundred thirty-one thousand, four hundred forty-nine".