20365665511 has 4 divisors (see below), whose sum is σ = 20472292224. Its totient is φ = 20259038800.

The previous prime is 20365665503. The next prime is 20365665521. The reversal of 20365665511 is 11556656302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20365665511 - 2³ = 20365665503 is a prime.

It is a super-2 number, since 2×20365665511² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20365665521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53313070 + ... + 53313451.

It is an arithmetic number, because the mean of its divisors is an integer number (5118073056).

Almost surely, 2^20365665511 is an apocalyptic number.

20365665511 is a deficient number, since it is larger than the sum of its proper divisors (106626713).

20365665511 is a wasteful number, since it uses less digits than its factorization.

20365665511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106626712.

The product of its (nonzero) digits is 162000, while the sum is 40.

The spelling of 20365665511 in words is "twenty billion, three hundred sixty-five million, six hundred sixty-five thousand, five hundred eleven".