664128 has 42 divisors (see below), whose sum is σ = 1905254. Its totient is φ = 221184.

The previous prime is 664123. The next prime is 664133. The reversal of 664128 is 821466.

664128 is a nontrivial binomial coefficient, being equal to C(1153, 2).

It is an interprime number because it is at equal distance from previous prime (664123) and next prime (664133).

It can be written as a sum of positive squares in only one way, i.e., 627264 + 36864 = 792^2 + 192^2 .

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

It is not an unprimeable number, because it can be changed into a prime (664121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1 + ... + 1152.

2⁶⁶⁴¹²⁸ is an apocalyptic number.

664128 is the 1152-nd triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (952627).

664128 is an abundant number, since it is smaller than the sum of its proper divisors (1241126).

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

664128 is a wasteful number, since it uses less digits than its factorization.

664128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171 (or 1158 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 664128 is about 814.9404886248. The cubic root of 664128 is about 87.2470189429.

The spelling of 664128 in words is "six hundred sixty-four thousand, one hundred twenty-eight".