20528336209 has 4 divisors (see below), whose sum is σ = 20602446004. Its totient is φ = 20454226416.

The previous prime is 20528336201. The next prime is 20528336221. The reversal of 20528336209 is 90263382502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1842813184 + 18685523025 = 42928^2 + 136695^2 .

It is a cyclic number.

It is not a de Polignac number, because 20528336209 - 2³ = 20528336201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20528336201) 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 in 3 ways as a sum of consecutive naturals, for example, 37054482 + ... + 37055035.

It is an arithmetic number, because the mean of its divisors is an integer number (5150611501).

Almost surely, 2^20528336209 is an apocalyptic number.

It is an amenable number.

20528336209 is a deficient number, since it is larger than the sum of its proper divisors (74109795).

20528336209 is an equidigital number, since it uses as much as digits as its factorization.

20528336209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74109794.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 20528336209 in words is "twenty billion, five hundred twenty-eight million, three hundred thirty-six thousand, two hundred nine".