66447 has 16 divisors (see below), whose sum is σ = 103680. Its totient is φ = 41976.

The previous prime is 66431. The next prime is 66449. The reversal of 66447 is 74466.

It is not a de Polignac number, because 66447 - 2⁴ = 66431 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

66447 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 66447.

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 66447.

It is not an unprimeable number, because it can be changed into a prime (66449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 568 + ... + 674.

It is an arithmetic number, because the mean of its divisors is an integer number (6480).

2⁶⁶⁴⁴⁷ is an apocalyptic number.

66447 is a deficient number, since it is larger than the sum of its proper divisors (37233).

66447 is a wasteful number, since it uses less digits than its factorization.

66447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 133 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 66447 is about 257.7731560888. The cubic root of 66447 is about 40.5034290649.

The spelling of 66447 in words is "sixty-six thousand, four hundred forty-seven".