20345165 has 4 divisors (see below), whose sum is σ = 24414204. Its totient is φ = 16276128.

The previous prime is 20345161. The next prime is 20345167. The reversal of 20345165 is 56154302.

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 5080516 + 15264649 = 2254^2 + 3907^2 .

It is a cyclic number.

It is not a de Polignac number, because 20345165 - 2² = 20345161 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 (20345161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2034512 + ... + 2034521.

It is an arithmetic number, because the mean of its divisors is an integer number (6103551).

Almost surely, 2^20345165 is an apocalyptic number.

It is an amenable number.

20345165 is a deficient number, since it is larger than the sum of its proper divisors (4069039).

20345165 is an equidigital number, since it uses as much as digits as its factorization.

20345165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4069038.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 20345165 is about 4510.5614949804. The cubic root of 20345165 is about 272.9944002751.

Adding to 20345165 its reverse (56154302), we get a palindrome (76499467).

The spelling of 20345165 in words is "twenty million, three hundred forty-five thousand, one hundred sixty-five".