20565320353 has 4 divisors (see below), whose sum is σ = 21121139860. Its totient is φ = 20009500848.

The previous prime is 20565320327. The next prime is 20565320371. The reversal of 20565320353 is 35302356502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7598260224 + 12967060129 = 87168^2 + 113873^2 .

It is a cyclic number.

It is not a de Polignac number, because 20565320353 - 2²¹ = 20563223201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20565320753) 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, 277909698 + ... + 277909771.

It is an arithmetic number, because the mean of its divisors is an integer number (5280284965).

Almost surely, 2^20565320353 is an apocalyptic number.

It is an amenable number.

20565320353 is a deficient number, since it is larger than the sum of its proper divisors (555819507).

20565320353 is an equidigital number, since it uses as much as digits as its factorization.

20565320353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555819506.

The product of its (nonzero) digits is 81000, while the sum is 34.

Adding to 20565320353 its reverse (35302356502), we get a palindrome (55867676855).

The spelling of 20565320353 in words is "twenty billion, five hundred sixty-five million, three hundred twenty thousand, three hundred fifty-three".