66783505689 has 12 divisors (see below), whose sum is σ = 96546759972. Its totient is φ = 44484631200.

The previous prime is 66783505673. The next prime is 66783505739. The reversal of 66783505689 is 98650538766.

66783505689 is a `hidden beast` number, since 6 + 67 + 8 + 3 + 5 + 0 + 568 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 41273985600 + 25509520089 = 203160^2 + 159717^2 .

It is not a de Polignac number, because 66783505689 - 2⁴ = 66783505673 is a prime.

It is a super-2 number, since 2×66783505689² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66783505609) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3130942 + ... + 3152199.

It is an arithmetic number, because the mean of its divisors is an integer number (8045563331).

Almost surely, 2^66783505689 is an apocalyptic number.

It is an amenable number.

66783505689 is a deficient number, since it is larger than the sum of its proper divisors (29763254283).

66783505689 is a wasteful number, since it uses less digits than its factorization.

66783505689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6284328 (or 6284325 counting only the distinct ones).

The product of its (nonzero) digits is 65318400, while the sum is 63.

The spelling of 66783505689 in words is "sixty-six billion, seven hundred eighty-three million, five hundred five thousand, six hundred eighty-nine".