20512165 has 16 divisors (see below), whose sum is σ = 25288560. Its totient is φ = 15966720.

The previous prime is 20512139. The next prime is 20512169. The reversal of 20512165 is 56121502.

It can be written as a sum of positive squares in 8 ways, for example, as 6140484 + 14371681 = 2478^2 + 3791^2 .

It is not a de Polignac number, because 20512165 - 2²³ = 12123557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20512169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32937 + ... + 33553.

It is an arithmetic number, because the mean of its divisors is an integer number (1580535).

Almost surely, 2^20512165 is an apocalyptic number.

It is an amenable number.

20512165 is a deficient number, since it is larger than the sum of its proper divisors (4776395).

20512165 is a wasteful number, since it uses less digits than its factorization.

20512165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 20512165 is about 4529.0357693443. The cubic root of 20512165 is about 273.7393092994.

Adding to 20512165 its reverse (56121502), we get a palindrome (76633667).

The spelling of 20512165 in words is "twenty million, five hundred twelve thousand, one hundred sixty-five".