66544 has 10 divisors (see below), whose sum is σ = 128960. Its totient is φ = 33264.

The previous prime is 66541. The next prime is 66553. The reversal of 66544 is 44566.

It is a happy number.

It is a plaindrome in base 9.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2064 + ... + 2095.

It is an arithmetic number, because the mean of its divisors is an integer number (12896).

2⁶⁶⁵⁴⁴ is an apocalyptic number.

It is an amenable number.

66544 is a deficient number, since it is larger than the sum of its proper divisors (62416).

66544 is a wasteful number, since it uses less digits than its factorization.

66544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4167 (or 4161 counting only the distinct ones).

The product of its digits is 2880, while the sum is 25.

The square root of 66544 is about 257.9612373982. The cubic root of 66544 is about 40.5231285868.

The spelling of 66544 in words is "sixty-six thousand, five hundred forty-four".