66000640 has 36 divisors (see below), whose sum is σ = 158095224. Its totient is φ = 26399744.

The previous prime is 66000631. The next prime is 66000653. The reversal of 66000640 is 4600066.

66000640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 24502 + ... + 27061.

It is an arithmetic number, because the mean of its divisors is an integer number (4391534).

Almost surely, 2^66000640 is an apocalyptic number.

It is an amenable number.

66000640 is an abundant number, since it is smaller than the sum of its proper divisors (92094584).

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

66000640 is an equidigital number, since it uses as much as digits as its factorization.

66000640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51584 (or 51570 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 66000640 is about 8124.0777938176. The cubic root of 66000640 is about 404.1253083174.

The spelling of 66000640 in words is "sixty-six million, six hundred forty", and thus it is an aban number.