66660738 has 8 divisors (see below), whose sum is σ = 133321488. Its totient is φ = 22220244.

The previous prime is 66660731. The next prime is 66660749. The reversal of 66660738 is 83706666.

66660738 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

66660738 is an admirable number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66660738.

It is not an unprimeable number, because it can be changed into a prime (66660731) by changing a digit.

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, 5555056 + ... + 5555067.

It is an arithmetic number, because the mean of its divisors is an integer number (16665186).

Almost surely, 2^66660738 is an apocalyptic number.

66660738 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

66660738 is a wasteful number, since it uses less digits than its factorization.

66660738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11110128.

The product of its (nonzero) digits is 217728, while the sum is 42.

The square root of 66660738 is about 8164.6027460006. The cubic root of 66660738 is about 405.4681128992.

The spelling of 66660738 in words is "sixty-six million, six hundred sixty thousand, seven hundred thirty-eight".