20660165 has 4 divisors (see below), whose sum is σ = 24792204. Its totient is φ = 16528128.

The previous prime is 20660161. The next prime is 20660173. The reversal of 20660165 is 56106602.

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 6806881 + 13853284 = 2609^2 + 3722^2 .

It is a cyclic number.

It is not a de Polignac number, because 20660165 - 2² = 20660161 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20660161) 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, 2066012 + ... + 2066021.

It is an arithmetic number, because the mean of its divisors is an integer number (6198051).

Almost surely, 2^20660165 is an apocalyptic number.

It is an amenable number.

20660165 is a deficient number, since it is larger than the sum of its proper divisors (4132039).

20660165 is an equidigital number, since it uses as much as digits as its factorization.

20660165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4132038.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20660165 is about 4545.3454214174. The cubic root of 20660165 is about 274.3960962776.

Adding to 20660165 its reverse (56106602), we get a palindrome (76766767).

The spelling of 20660165 in words is "twenty million, six hundred sixty thousand, one hundred sixty-five".