66686365 has 16 divisors (see below), whose sum is σ = 81365040. Its totient is φ = 52462080.

The previous prime is 66686357. The next prime is 66686369. The reversal of 66686365 is 56368666.

It can be written as a sum of positive squares in 8 ways, for example, as 13527684 + 53158681 = 3678^2 + 7291^2 .

It is not a de Polignac number, because 66686365 - 2³ = 66686357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66686369) 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, 122995 + ... + 123535.

It is an arithmetic number, because the mean of its divisors is an integer number (5085315).

Almost surely, 2^66686365 is an apocalyptic number.

It is an amenable number.

66686365 is a deficient number, since it is larger than the sum of its proper divisors (14678675).

66686365 is a wasteful number, since it uses less digits than its factorization.

66686365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912.

The product of its digits is 933120, while the sum is 46.

The square root of 66686365 is about 8166.1719918209. The cubic root of 66686365 is about 405.5200655196.

The spelling of 66686365 in words is "sixty-six million, six hundred eighty-six thousand, three hundred sixty-five".