20564863 has 8 divisors (see below), whose sum is σ = 22815360. Its totient is φ = 18377880.

The previous prime is 20564839. The next prime is 20564867. The reversal of 20564863 is 36846502.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20564863 - 2¹³ = 20556671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564867) 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 7 ways as a sum of consecutive naturals, for example, 15195 + ... + 16492.

It is an arithmetic number, because the mean of its divisors is an integer number (2851920).

Almost surely, 2^20564863 is an apocalyptic number.

20564863 is a deficient number, since it is larger than the sum of its proper divisors (2250497).

20564863 is a wasteful number, since it uses less digits than its factorization.

20564863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31757.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 20564863 is about 4534.8498321334. The cubic root of 20564863 is about 273.9735309292.

The spelling of 20564863 in words is "twenty million, five hundred sixty-four thousand, eight hundred sixty-three".