20205221513 has 2 divisors, whose sum is σ = 20205221514. Its totient is φ = 20205221512.

The previous prime is 20205221489. The next prime is 20205221527. The reversal of 20205221513 is 31512250202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15007965049 + 5197256464 = 122507^2 + 72092^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20205221513 is a prime.

It is not a weakly prime, because it can be changed into another prime (20205221563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10102610756 + 10102610757.

It is an arithmetic number, because the mean of its divisors is an integer number (10102610757).

Almost surely, 2^20205221513 is an apocalyptic number.

It is an amenable number.

20205221513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20205221513 is an equidigital number, since it uses as much as digits as its factorization.

20205221513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 20205221513 its reverse (31512250202), we get a palindrome (51717471715).

The spelling of 20205221513 in words is "twenty billion, two hundred five million, two hundred twenty-one thousand, five hundred thirteen".