20561344 has 56 divisors (see below), whose sum is σ = 44206160. Its totient is φ = 9455616.

The previous prime is 20561329. The next prime is 20561351. The reversal of 20561344 is 44316502.

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 7 ways as a sum of consecutive naturals, for example, 44764 + ... + 45220.

Almost surely, 2^20561344 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 20561344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22103080).

20561344 is an abundant number, since it is smaller than the sum of its proper divisors (23644816).

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

20561344 is a wasteful number, since it uses less digits than its factorization.

20561344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20561344 is about 4534.4618203266. The cubic root of 20561344 is about 273.9579028511.

Adding to 20561344 its reverse (44316502), we get a palindrome (64877846).

The spelling of 20561344 in words is "twenty million, five hundred sixty-one thousand, three hundred forty-four".