66750640 has 40 divisors (see below), whose sum is σ = 169306128. Its totient is φ = 24272640.

The previous prime is 66750637. The next prime is 66750661. The reversal of 66750640 is 4605766.

66750640 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 a junction number, because it is equal to n+sod(n) for n = 66750596 and 66750605.

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, 37047 + ... + 38806.

Almost surely, 2^66750640 is an apocalyptic number.

It is an amenable number.

66750640 is an abundant number, since it is smaller than the sum of its proper divisors (102555488).

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

66750640 is a wasteful number, since it uses less digits than its factorization.

66750640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75877 (or 75871 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 66750640 is about 8170.1064864541. The cubic root of 66750640 is about 405.6503091988.

The spelling of 66750640 in words is "sixty-six million, seven hundred fifty thousand, six hundred forty".