20579689 has 4 divisors (see below), whose sum is σ = 22162756. Its totient is φ = 18996624.

The previous prime is 20579683. The next prime is 20579693. The reversal of 20579689 is 98697502.

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 4515625 + 16064064 = 2125^2 + 4008^2 .

It is a cyclic number.

It is not a de Polignac number, because 20579689 - 2⁹ = 20579177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20579683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 791514 + ... + 791539.

It is an arithmetic number, because the mean of its divisors is an integer number (5540689).

Almost surely, 2^20579689 is an apocalyptic number.

It is an amenable number.

20579689 is a deficient number, since it is larger than the sum of its proper divisors (1583067).

20579689 is a wasteful number, since it uses less digits than its factorization.

20579689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583066.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 20579689 is about 4536.4842113690. The cubic root of 20579689 is about 274.0393544624.

The spelling of 20579689 in words is "twenty million, five hundred seventy-nine thousand, six hundred eighty-nine".