20717056 has 40 divisors (see below), whose sum is σ = 42401304. Its totient is φ = 10106880.

The previous prime is 20717041. The next prime is 20717057. The reversal of 20717056 is 65071702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717057) 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, 21546 + ... + 22486.

Almost surely, 2^20717056 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 20717056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21200652).

20717056 is an abundant number, since it is smaller than the sum of its proper divisors (21684248).

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

20717056 is an frugal number, since it uses more digits than its factorization.

20717056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1002 (or 986 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 20717056 is about 4551.5992793742. The cubic root of 20717056 is about 274.6477296566.

Adding to 20717056 its reverse (65071702), we get a palindrome (85788758).

The spelling of 20717056 in words is "twenty million, seven hundred seventeen thousand, fifty-six".