20528456489 has 2 divisors, whose sum is σ = 20528456490. Its totient is φ = 20528456488.

The previous prime is 20528456477. The next prime is 20528456503. The reversal of 20528456489 is 98465482502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19967950864 + 560505625 = 141308^2 + 23675^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20528456489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20528456489.

It is not a weakly prime, because it can be changed into another prime (20528453489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264228244 + 10264228245.

It is an arithmetic number, because the mean of its divisors is an integer number (10264228245).

Almost surely, 2^20528456489 is an apocalyptic number.

It is an amenable number.

20528456489 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528456489 is an equidigital number, since it uses as much as digits as its factorization.

20528456489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5529600, while the sum is 53.

The spelling of 20528456489 in words is "twenty billion, five hundred twenty-eight million, four hundred fifty-six thousand, four hundred eighty-nine".