66786698138 has 8 divisors (see below), whose sum is σ = 100186273332. Its totient is φ = 33391273696.

The previous prime is 66786698089. The next prime is 66786698141. The reversal of 66786698138 is 83189668766.

66786698138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 65003071849 + 1783626289 = 254957^2 + 42233^2 .

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997145 + ... + 1062012.

Almost surely, 2^66786698138 is an apocalyptic number.

66786698138 is a deficient number, since it is larger than the sum of its proper divisors (33399575194).

66786698138 is a wasteful number, since it uses less digits than its factorization.

66786698138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075376.

The product of its digits is 125411328, while the sum is 68.

The spelling of 66786698138 in words is "sixty-six billion, seven hundred eighty-six million, six hundred ninety-eight thousand, one hundred thirty-eight".