66551328 has 192 divisors, whose sum is σ = 215550720. Its totient is φ = 19869696.

The previous prime is 66551321. The next prime is 66551333. The reversal of 66551328 is 82315566.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66551292 and 66551301.

It is not an unprimeable number, because it can be changed into a prime (66551321) 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, 337726 + ... + 337922.

It is an arithmetic number, because the mean of its divisors is an integer number (1122660).

Almost surely, 2^66551328 is an apocalyptic number.

66551328 is a gapful number since it is divisible by the number (68) 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 66551328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107775360).

66551328 is an abundant number, since it is smaller than the sum of its proper divisors (148999392).

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

66551328 is a wasteful number, since it uses less digits than its factorization.

66551328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 242 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 66551328 is about 8157.8997297098. The cubic root of 66551328 is about 405.2461603663.

The spelling of 66551328 in words is "sixty-six million, five hundred fifty-one thousand, three hundred twenty-eight".