20365665505 has 16 divisors (see below), whose sum is σ = 24568637184. Its totient is φ = 16206194880.

The previous prime is 20365665503. The next prime is 20365665521. The reversal of 20365665505 is 50556656302.

It is not a de Polignac number, because 20365665505 - 2¹ = 20365665503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20365665503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 743839 + ... + 770731.

It is an arithmetic number, because the mean of its divisors is an integer number (1535539824).

Almost surely, 2^20365665505 is an apocalyptic number.

It is an amenable number.

20365665505 is a deficient number, since it is larger than the sum of its proper divisors (4202971679).

20365665505 is a wasteful number, since it uses less digits than its factorization.

20365665505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27696.

The product of its (nonzero) digits is 810000, while the sum is 43.

The spelling of 20365665505 in words is "twenty billion, three hundred sixty-five million, six hundred sixty-five thousand, five hundred five".