20505385529 has 2 divisors, whose sum is σ = 20505385530. Its totient is φ = 20505385528.

The previous prime is 20505385517. The next prime is 20505385541. The reversal of 20505385529 is 92558350502.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (20505385517) and next prime (20505385541).

It can be written as a sum of positive squares in only one way, i.e., 15165429904 + 5339955625 = 123148^2 + 73075^2 .

It is a cyclic number.

It is not a de Polignac number, because 20505385529 - 2¹² = 20505381433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20505385529.

It is not a weakly prime, because it can be changed into another prime (20505385429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10252692764 + 10252692765.

It is an arithmetic number, because the mean of its divisors is an integer number (10252692765).

Almost surely, 2^20505385529 is an apocalyptic number.

It is an amenable number.

20505385529 is a deficient number, since it is larger than the sum of its proper divisors (1).

20505385529 is an equidigital number, since it uses as much as digits as its factorization.

20505385529 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540000, while the sum is 44.

The spelling of 20505385529 in words is "twenty billion, five hundred five million, three hundred eighty-five thousand, five hundred twenty-nine".