20465565 has 16 divisors (see below), whose sum is σ = 34468800. Its totient is φ = 10340352.

The previous prime is 20465563. The next prime is 20465587. The reversal of 20465565 is 56556402.

It is a happy number.

It is not a de Polignac number, because 20465565 - 2¹ = 20465563 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20465563) 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 15 ways as a sum of consecutive naturals, for example, 35620 + ... + 36189.

It is an arithmetic number, because the mean of its divisors is an integer number (2154300).

Almost surely, 2^20465565 is an apocalyptic number.

It is an amenable number.

20465565 is a deficient number, since it is larger than the sum of its proper divisors (14003235).

20465565 is a wasteful number, since it uses less digits than its factorization.

20465565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71836.

The product of its (nonzero) digits is 36000, while the sum is 33.

The square root of 20465565 is about 4523.8882612195. Note that the first 3 decimals coincide. The cubic root of 20465565 is about 273.5318564049.

The spelling of 20465565 in words is "twenty million, four hundred sixty-five thousand, five hundred sixty-five".