20565280836 has 135 divisors (see below), whose sum is σ = 55768894797. Its totient is φ = 6608148480.

The previous prime is 20565280759. The next prime is 20565280861. The reversal of 20565280836 is 63808256502.

The square root of 20565280836 is 143406.

It is a perfect power (a square), and thus also a powerful number.

20565280836 is a `hidden beast` number, since 2 + 0 + 565 + 2 + 8 + 0 + 83 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20246444100 + 318836736 = 142290^2 + 17856^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20565280791 and 20565280800.

It is an unprimeable number.

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 in 44 ways as a sum of consecutive naturals, for example, 80020420 + ... + 80020676.

Almost surely, 2^20565280836 is an apocalyptic number.

20565280836 is the 143406-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20565280836

20565280836 is an abundant number, since it is smaller than the sum of its proper divisors (35203613961).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20565280836 is an equidigital number, since it uses as much as digits as its factorization.

20565280836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

It can be divided in two parts, 20565 and 280836, that added together give a square (301401 = 549²).

The spelling of 20565280836 in words is "twenty billion, five hundred sixty-five million, two hundred eighty thousand, eight hundred thirty-six".