20564161 has 8 divisors (see below), whose sum is σ = 21340800. Its totient is φ = 19792080.

The previous prime is 20564147. The next prime is 20564171. The reversal of 20564161 is 16146502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20564161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20564171) 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 7 ways as a sum of consecutive naturals, for example, 10056 + ... + 11926.

It is an arithmetic number, because the mean of its divisors is an integer number (2667600).

Almost surely, 2^20564161 is an apocalyptic number.

It is an amenable number.

20564161 is a deficient number, since it is larger than the sum of its proper divisors (776639).

20564161 is a wasteful number, since it uses less digits than its factorization.

20564161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2279.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20564161 is about 4534.7724308944. The cubic root of 20564161 is about 273.9704134498.

The spelling of 20564161 in words is "twenty million, five hundred sixty-four thousand, one hundred sixty-one".