667090728 has 80 divisors (see below), whose sum is σ = 1887912180. Its totient is φ = 220050432.

The previous prime is 667090681. The next prime is 667090747. The reversal of 667090728 is 827090766.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 589615524 + 77475204 = 24282^2 + 8802^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 57550 + ... + 68162.

Almost surely, 2^667090728 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 667090728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (943956090).

667090728 is an abundant number, since it is smaller than the sum of its proper divisors (1220821452).

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

667090728 is a wasteful number, since it uses less digits than its factorization.

667090728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10728 (or 10715 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 667090728 is about 25828.0995816572. The cubic root of 667090728 is about 873.7656513249.

The spelling of 667090728 in words is "six hundred sixty-seven million, ninety thousand, seven hundred twenty-eight".