81447 has 8 divisors (see below), whose sum is σ = 115056. Its totient is φ = 51072.

The previous prime is 81439. The next prime is 81457. The reversal of 81447 is 74418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81447 - 2³ = 81439 is a prime.

It is a super-2 number, since 2×81447² = 13267227618, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81447.

It is not an unprimeable number, because it can be changed into a prime (81457) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 748 + ... + 849.

It is an arithmetic number, because the mean of its divisors is an integer number (14382).

2⁸¹⁴⁴⁷ is an apocalyptic number.

81447 is a deficient number, since it is larger than the sum of its proper divisors (33609).

81447 is a wasteful number, since it uses less digits than its factorization.

81447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617.

The product of its digits is 896, while the sum is 24.

The square root of 81447 is about 285.3892079249. The cubic root of 81447 is about 43.3469319583.

It can be divided in two parts, 814 and 47, that added together give a triangular number (861 = T₄₁).

The spelling of 81447 in words is "eighty-one thousand, four hundred forty-seven".