66624 has 28 divisors (see below), whose sum is σ = 176784. Its totient is φ = 22144.

The previous prime is 66617. The next prime is 66629. The reversal of 66624 is 42666.

66624 = 82² + 83² + ... + 90².

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 66594 and 66603.

It is not an unprimeable number, because it can be changed into a prime (66629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19 + ... + 365.

2⁶⁶⁶²⁴ is an apocalyptic number.

66624 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88392).

66624 is an abundant number, since it is smaller than the sum of its proper divisors (110160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66624 is a wasteful number, since it uses less digits than its factorization.

66624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 352 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 66624 is about 258.1162528784. The cubic root of 66624 is about 40.5393612149.

It can be divided in two parts, 6662 and 4, that added together give a palindrome (6666).

The spelling of 66624 in words is "sixty-six thousand, six hundred twenty-four".