20528638769 has 2 divisors, whose sum is σ = 20528638770. Its totient is φ = 20528638768.

The previous prime is 20528638733. The next prime is 20528638817. The reversal of 20528638769 is 96783682502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19289598769 + 1239040000 = 138887^2 + 35200^2 .

It is a cyclic number.

It is not a de Polignac number, because 20528638769 - 2²⁴ = 20511861553 is a prime.

It is a super-2 number, since 2×20528638769² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20528631769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264319384 + 10264319385.

It is an arithmetic number, because the mean of its divisors is an integer number (10264319385).

Almost surely, 2^20528638769 is an apocalyptic number.

It is an amenable number.

20528638769 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528638769 is an equidigital number, since it uses as much as digits as its factorization.

20528638769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8709120, while the sum is 56.

The spelling of 20528638769 in words is "twenty billion, five hundred twenty-eight million, six hundred thirty-eight thousand, seven hundred sixty-nine".