20564928 has 70 divisors (see below), whose sum is σ = 60976256. Its totient is φ = 6853248.

The previous prime is 20564923. The next prime is 20564941. The reversal of 20564928 is 82946502.

It is a happy number.

20564928 is a `hidden beast` number, since 2 + 0 + 5 + 649 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20564892 and 20564901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564923) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3201 + ... + 7167.

Almost surely, 2^20564928 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 20564928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30488128).

20564928 is an abundant number, since it is smaller than the sum of its proper divisors (40411328).

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

20564928 is an equidigital number, since it uses as much as digits as its factorization.

20564928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3991 (or 3972 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 20564928 is about 4534.8569988479. The cubic root of 20564928 is about 273.9738195811.

The spelling of 20564928 in words is "twenty million, five hundred sixty-four thousand, nine hundred twenty-eight".