20105165 has 4 divisors (see below), whose sum is σ = 24126204. Its totient is φ = 16084128.

The previous prime is 20105147. The next prime is 20105191. The reversal of 20105165 is 56150102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56150102 = 2 ⋅28075051.

It can be written as a sum of positive squares in 2 ways, for example, as 5004169 + 15100996 = 2237^2 + 3886^2 .

It is a cyclic number.

It is not a de Polignac number, because 20105165 - 2¹⁰ = 20104141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2010512 + ... + 2010521.

It is an arithmetic number, because the mean of its divisors is an integer number (6031551).

Almost surely, 2^20105165 is an apocalyptic number.

It is an amenable number.

20105165 is a deficient number, since it is larger than the sum of its proper divisors (4021039).

20105165 is an equidigital number, since it uses as much as digits as its factorization.

20105165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4021038.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 20105165 is about 4483.8783435771. The cubic root of 20105165 is about 271.9166997297.

Adding to 20105165 its reverse (56150102), we get a palindrome (76255267).

The spelling of 20105165 in words is "twenty million, one hundred five thousand, one hundred sixty-five".