667128 has 96 divisors (see below), whose sum is σ = 2194560. Its totient is φ = 164160.

The previous prime is 667127. The next prime is 667129. The reversal of 667128 is 821766.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (667127) and next prime (667129).

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

Its product of digits (4032) is a multiple of the sum of its prime divisors (42).

It is a junction number, because it is equal to n+sod(n) for n = 667095 and 667104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35103 + ... + 35121.

It is an arithmetic number, because the mean of its divisors is an integer number (22860).

2⁶⁶⁷¹²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1097280).

667128 is an abundant number, since it is smaller than the sum of its proper divisors (1527432).

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

667128 is a wasteful number, since it uses less digits than its factorization.

667128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 42 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 667128 is about 816.7790398878. The cubic root of 667128 is about 87.3781924167.

The spelling of 667128 in words is "six hundred sixty-seven thousand, one hundred twenty-eight".