66685839 has 16 divisors (see below), whose sum is σ = 102103680. Its totient is φ = 38288160.

The previous prime is 66685823. The next prime is 66685859. The reversal of 66685839 is 93858666.

It is not a de Polignac number, because 66685839 - 2⁴ = 66685823 is a prime.

It is a super-2 number, since 2×66685839² = 8894002246267842, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66685791 and 66685800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66685859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52552 + ... + 53805.

It is an arithmetic number, because the mean of its divisors is an integer number (6381480).

Almost surely, 2^66685839 is an apocalyptic number.

66685839 is a deficient number, since it is larger than the sum of its proper divisors (35417841).

66685839 is a wasteful number, since it uses less digits than its factorization.

66685839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106390.

The product of its digits is 1866240, while the sum is 51.

The square root of 66685839 is about 8166.1397857250. The cubic root of 66685839 is about 405.5189993140.

The spelling of 66685839 in words is "sixty-six million, six hundred eighty-five thousand, eight hundred thirty-nine".