81446447 has 4 divisors (see below), whose sum is σ = 81475680. Its totient is φ = 81417216.

The previous prime is 81446383. The next prime is 81446461. The reversal of 81446447 is 74464418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81446447 - 2⁶ = 81446383 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81446447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81446467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9938 + ... + 16175.

It is an arithmetic number, because the mean of its divisors is an integer number (20368920).

Almost surely, 2^81446447 is an apocalyptic number.

81446447 is a deficient number, since it is larger than the sum of its proper divisors (29233).

81446447 is a wasteful number, since it uses less digits than its factorization.

81446447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29232.

The product of its digits is 86016, while the sum is 38.

The square root of 81446447 is about 9024.7685288876. The cubic root of 81446447 is about 433.4683385396.

The spelling of 81446447 in words is "eighty-one million, four hundred forty-six thousand, four hundred forty-seven".