66645240 has 64 divisors (see below), whose sum is σ = 200806560. Its totient is φ = 17694720.

The previous prime is 66645233. The next prime is 66645259. The reversal of 66645240 is 4254666.

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 15 ways as a sum of consecutive naturals, for example, 29760 + ... + 31920.

Almost surely, 2^66645240 is an apocalyptic number.

66645240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66645240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100403280).

66645240 is an abundant number, since it is smaller than the sum of its proper divisors (134161320).

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

66645240 is a wasteful number, since it uses less digits than its factorization.

66645240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2432 (or 2428 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 66645240 is about 8163.6535938267. The cubic root of 66645240 is about 405.4366879452.

The spelling of 66645240 in words is "sixty-six million, six hundred forty-five thousand, two hundred forty".