66666365 has 4 divisors (see below), whose sum is σ = 79999644. Its totient is φ = 53333088.

The previous prime is 66666361. The next prime is 66666371. The reversal of 66666365 is 56366666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8082649 + 58583716 = 2843^2 + 7654^2 .

It is a cyclic number.

It is not a de Polignac number, because 66666365 - 2² = 66666361 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6666632 + ... + 6666641.

It is an arithmetic number, because the mean of its divisors is an integer number (19999911).

Almost surely, 2^66666365 is an apocalyptic number.

It is an amenable number.

66666365 is a deficient number, since it is larger than the sum of its proper divisors (13333279).

66666365 is a wasteful number, since it uses less digits than its factorization.

66666365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13333278.

The product of its digits is 699840, while the sum is 44.

The square root of 66666365 is about 8164.9473360212. The cubic root of 66666365 is about 405.4795214381.

It can be divided in two parts, 6666 and 6365, that added together give a palindrome (13031).

The spelling of 66666365 in words is "sixty-six million, six hundred sixty-six thousand, three hundred sixty-five".