66689000 has 96 divisors (see below), whose sum is σ = 181663560. Its totient is φ = 22848000.

The previous prime is 66688991. The next prime is 66689017. The reversal of 66689000 is 98666.

It can be written as a sum of positive squares in 4 ways, for example, as 9746884 + 56942116 = 3122^2 + 7546^2 .

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 48320 + ... + 49680.

Almost surely, 2^66689000 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 66689000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90831780).

66689000 is an abundant number, since it is smaller than the sum of its proper divisors (114974560).

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

66689000 is a wasteful number, since it uses less digits than its factorization.

66689000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396 (or 1375 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 66689000 is about 8166.3333265303. Note that the first 4 decimals coincide. The cubic root of 66689000 is about 405.5254065979.

The spelling of 66689000 in words is "sixty-six million, six hundred eighty-nine thousand".