66603440 has 40 divisors (see below), whose sum is σ = 156405168. Its totient is φ = 26374400.

The previous prime is 66603403. The next prime is 66603451. The reversal of 66603440 is 4430666.

66603440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3959 + ... + 12201.

Almost surely, 2^66603440 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 66603440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78202584).

66603440 is an abundant number, since it is smaller than the sum of its proper divisors (89801728).

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

66603440 is a wasteful number, since it uses less digits than its factorization.

66603440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8357 (or 8351 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 66603440 is about 8161.0930640448. The cubic root of 66603440 is about 405.3519067070.

The spelling of 66603440 in words is "sixty-six million, six hundred three thousand, four hundred forty".