666689328 has 60 divisors (see below), whose sum is σ = 1964012440. Its totient is φ = 210532608.

The previous prime is 666689267. The next prime is 666689341. The reversal of 666689328 is 823986666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119101 + ... + 124572.

Almost surely, 2^666689328 is an apocalyptic number.

It is an amenable number.

666689328 is an abundant number, since it is smaller than the sum of its proper divisors (1297323112).

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

666689328 is a wasteful number, since it uses less digits than its factorization.

666689328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243706 (or 243697 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The square root of 666689328 is about 25820.3278058200. The cubic root of 666689328 is about 873.5903628732.

The spelling of 666689328 in words is "six hundred sixty-six million, six hundred eighty-nine thousand, three hundred twenty-eight".