20528689 has 2 divisors, whose sum is σ = 20528690. Its totient is φ = 20528688.

The previous prime is 20528687. The next prime is 20528701. The reversal of 20528689 is 98682502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13727025 + 6801664 = 3705^2 + 2608^2 .

It is a cyclic number.

It is not a de Polignac number, because 20528689 - 2¹ = 20528687 is a prime.

Together with 20528687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20528687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264344 + 10264345.

It is an arithmetic number, because the mean of its divisors is an integer number (10264345).

Almost surely, 2^20528689 is an apocalyptic number.

It is an amenable number.

20528689 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528689 is an equidigital number, since it uses as much as digits as its factorization.

20528689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 20528689 is about 4530.8596314607. The cubic root of 20528689 is about 273.8127950299.

The spelling of 20528689 in words is "twenty million, five hundred twenty-eight thousand, six hundred eighty-nine".