20709568 has 56 divisors (see below), whose sum is σ = 46817280. Its totient is φ = 8997120.

The previous prime is 20709547. The next prime is 20709569. The reversal of 20709568 is 86590702.

It is not an unprimeable number, because it can be changed into a prime (20709569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15553 + ... + 16831.

Almost surely, 2^20709568 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 20709568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23408640).

20709568 is an abundant number, since it is smaller than the sum of its proper divisors (26107712).

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

20709568 is a wasteful number, since it uses less digits than its factorization.

20709568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1325 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 20709568 is about 4550.7766370148. The cubic root of 20709568 is about 274.6146359901.

The spelling of 20709568 in words is "twenty million, seven hundred nine thousand, five hundred sixty-eight".