20385564 has 12 divisors (see below), whose sum is σ = 47566344. Its totient is φ = 6795184.

The previous prime is 20385559. The next prime is 20385571. The reversal of 20385564 is 46558302.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 849387 + ... + 849410.

It is an arithmetic number, because the mean of its divisors is an integer number (3963862).

Almost surely, 2^20385564 is an apocalyptic number.

It is an amenable number.

20385564 is an abundant number, since it is smaller than the sum of its proper divisors (27180780).

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

20385564 is a wasteful number, since it uses less digits than its factorization.

20385564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698804 (or 1698802 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 20385564 is about 4515.0375413722. The cubic root of 20385564 is about 273.1749740379.

The spelling of 20385564 in words is "twenty million, three hundred eighty-five thousand, five hundred sixty-four".