20540565 has 12 divisors (see below), whose sum is σ = 35603724. Its totient is φ = 10954944.

The previous prime is 20540561. The next prime is 20540579. The reversal of 20540565 is 56504502.

It can be written as a sum of positive squares in 2 ways, for example, as 8803089 + 11737476 = 2967^2 + 3426^2 .

It is not a de Polignac number, because 20540565 - 2² = 20540561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540561) 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 11 ways as a sum of consecutive naturals, for example, 228184 + ... + 228273.

It is an arithmetic number, because the mean of its divisors is an integer number (2966977).

Almost surely, 2^20540565 is an apocalyptic number.

It is an amenable number.

20540565 is a deficient number, since it is larger than the sum of its proper divisors (15063159).

20540565 is a wasteful number, since it uses less digits than its factorization.

20540565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456468 (or 456465 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 27.

The square root of 20540565 is about 4532.1700100504. The cubic root of 20540565 is about 273.8655857673.

The spelling of 20540565 in words is "twenty million, five hundred forty thousand, five hundred sixty-five".