66613165 has 4 divisors (see below), whose sum is σ = 79935804. Its totient is φ = 53290528.

The previous prime is 66613163. The next prime is 66613177. The reversal of 66613165 is 56131666.

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 48525156 + 18088009 = 6966^2 + 4253^2 .

It is a cyclic number.

It is not a de Polignac number, because 66613165 - 2¹ = 66613163 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66613165.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66613163) 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, 6661312 + ... + 6661321.

It is an arithmetic number, because the mean of its divisors is an integer number (19983951).

Almost surely, 2^66613165 is an apocalyptic number.

It is an amenable number.

66613165 is a deficient number, since it is larger than the sum of its proper divisors (13322639).

66613165 is a wasteful number, since it uses less digits than its factorization.

66613165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13322638.

The product of its digits is 19440, while the sum is 34.

The square root of 66613165 is about 8161.6888570932. The cubic root of 66613165 is about 405.3716346942.

It can be divided in two parts, 666 and 13165, that added together give a palindrome (13831).

The spelling of 66613165 in words is "sixty-six million, six hundred thirteen thousand, one hundred sixty-five".