20569321 has 4 divisors (see below), whose sum is σ = 20582100. Its totient is φ = 20556544.

The previous prime is 20569273. The next prime is 20569327. The reversal of 20569321 is 12396502.

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 4247721 + 16321600 = 2061^2 + 4040^2 .

It is a cyclic number.

It is not a de Polignac number, because 20569321 - 2⁷ = 20569193 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20569321.

It is not an unprimeable number, because it can be changed into a prime (20569327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3556 + ... + 7333.

It is an arithmetic number, because the mean of its divisors is an integer number (5145525).

Almost surely, 2^20569321 is an apocalyptic number.

It is an amenable number.

20569321 is a deficient number, since it is larger than the sum of its proper divisors (12779).

20569321 is a wasteful number, since it uses less digits than its factorization.

20569321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12778.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 20569321 is about 4535.3413322483. The cubic root of 20569321 is about 273.9933265997.

The spelling of 20569321 in words is "twenty million, five hundred sixty-nine thousand, three hundred twenty-one".