20165320545 has 16 divisors (see below), whose sum is σ = 32273928960. Its totient is φ = 10751698944.

The previous prime is 20165320537. The next prime is 20165320547. The reversal of 20165320545 is 54502356102.

It is not a de Polignac number, because 20165320545 - 2³ = 20165320537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20165320547) 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, 142585 + ... + 246294.

It is an arithmetic number, because the mean of its divisors is an integer number (2017120560).

Almost surely, 2^20165320545 is an apocalyptic number.

It is an amenable number.

20165320545 is a deficient number, since it is larger than the sum of its proper divisors (12108608415).

20165320545 is a wasteful number, since it uses less digits than its factorization.

20165320545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392344.

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

Adding to 20165320545 its reverse (54502356102), we get a palindrome (74667676647).

The spelling of 20165320545 in words is "twenty billion, one hundred sixty-five million, three hundred twenty thousand, five hundred forty-five".