66553380 has 96 divisors (see below), whose sum is σ = 212714880.
Its totient is φ = 17262720.
The previous prime is 66553369. The next prime is 66553381. The reversal of 66553380 is 8335566.
It can be divided in two parts, 665 and 53380, that added together give a palindrome (54045).
It is a Harshad number since it is a multiple of its sum of digits (36).
It is not an unprimeable number, because it can be changed into a prime (66553381) by changing a digit.
It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18315 + ... + 21645.
It is an arithmetic number, because the mean of its divisors is an integer number (2215780).
Almost surely, 266553380 is an apocalyptic number.
66553380 is a gapful number since it is divisible by the number (60) 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 66553380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106357440).
66553380 is an abundant number, since it is smaller than the sum of its proper divisors (146161500).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
66553380 is a wasteful number, since it uses less digits than its factorization.
66553380 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3386 (or 3378 counting only the distinct ones).
The product of its (nonzero) digits is 64800, while the sum is 36.
The square root of 66553380 is about 8158.0254964054.
The cubic root of 66553380 is about 405.2503253549.
The spelling of 66553380 in words is "sixty-six million, five hundred fifty-three thousand, three hundred eighty".