66845688 has 128 divisors (see below), whose sum is σ = 208158720. Its totient is φ = 17418240.

The previous prime is 66845687. The next prime is 66845689. The reversal of 66845688 is 88654866.

It is an interprime number because it is at equal distance from previous prime (66845687) and next prime (66845689).

It is a self number, because there is not a number n which added to its sum of digits gives 66845688.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66845687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 277248 + ... + 277488.

It is an arithmetic number, because the mean of its divisors is an integer number (1626240).

Almost surely, 2^66845688 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 66845688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104079360).

66845688 is an abundant number, since it is smaller than the sum of its proper divisors (141313032).

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

66845688 is a wasteful number, since it uses less digits than its factorization.

66845688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397 (or 393 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 51.

The square root of 66845688 is about 8175.9212324973. The cubic root of 66845688 is about 405.8427566152.

The spelling of 66845688 in words is "sixty-six million, eight hundred forty-five thousand, six hundred eighty-eight".