20203265521 has 2 divisors, whose sum is σ = 20203265522. Its totient is φ = 20203265520.

The previous prime is 20203265519. The next prime is 20203265561. The reversal of 20203265521 is 12556230202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13689000000 + 6514265521 = 117000^2 + 80711^2 .

It is a cyclic number.

It is not a de Polignac number, because 20203265521 - 2¹ = 20203265519 is a prime.

Together with 20203265519, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20203265521.

It is not a weakly prime, because it can be changed into another prime (20203265561) 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 as a sum of consecutive naturals, namely, 10101632760 + 10101632761.

It is an arithmetic number, because the mean of its divisors is an integer number (10101632761).

Almost surely, 2^20203265521 is an apocalyptic number.

It is an amenable number.

20203265521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20203265521 is an equidigital number, since it uses as much as digits as its factorization.

20203265521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 20203265521 its reverse (12556230202), we get a palindrome (32759495723).

The spelling of 20203265521 in words is "twenty billion, two hundred three million, two hundred sixty-five thousand, five hundred twenty-one".