20569856 has 36 divisors (see below), whose sum is σ = 43230600. Its totient is φ = 9741312.

The previous prime is 20569849. The next prime is 20569859. The reversal of 20569856 is 65896502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20569859) 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, 2750 + ... + 6978.

It is an arithmetic number, because the mean of its divisors is an integer number (1200850).

Almost surely, 2^20569856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20569856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21615300).

20569856 is an abundant number, since it is smaller than the sum of its proper divisors (22660744).

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

20569856 is an equidigital number, since it uses as much as digits as its factorization.

20569856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4264 (or 4250 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 41.

The square root of 20569856 is about 4535.4003130925. The cubic root of 20569856 is about 273.9957020655.

The spelling of 20569856 in words is "twenty million, five hundred sixty-nine thousand, eight hundred fifty-six".