66550 has 24 divisors (see below), whose sum is σ = 136152. Its totient is φ = 24200.

The previous prime is 66541. The next prime is 66553. The reversal of 66550 is 5566.

It is a Harshad number since it is a multiple of its sum of digits (22).

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 (66553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6045 + ... + 6055.

It is an arithmetic number, because the mean of its divisors is an integer number (5673).

2⁶⁶⁵⁵⁰ is an apocalyptic number.

66550 is an abundant number, since it is smaller than the sum of its proper divisors (69602).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68076).

66550 is a wasteful number, since it uses less digits than its factorization.

66550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 66550 is about 257.9728667903. The cubic root of 66550 is about 40.5243464850.

Multiplying 66550 by its sum of digits (22), we get a square (1464100 = 1210²).

66550 divided by its sum of digits (22) gives a square (3025 = 55²).

It can be divided in two parts, 66 and 550, that added together give a palindrome (616).

The spelling of 66550 in words is "sixty-six thousand, five hundred fifty".