20717968 has 40 divisors (see below), whose sum is σ = 43256160. Its totient is φ = 9576960.

The previous prime is 20717953. The next prime is 20717969. The reversal of 20717968 is 86971702.

It is a self number, because there is not a number n which added to its sum of digits gives 20717968.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15403 + ... + 16693.

It is an arithmetic number, because the mean of its divisors is an integer number (1081404).

Almost surely, 2^20717968 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 20717968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21628080).

20717968 is an abundant number, since it is smaller than the sum of its proper divisors (22538192).

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

20717968 is a wasteful number, since it uses less digits than its factorization.

20717968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1375 (or 1369 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 20717968 is about 4551.6994628380. The cubic root of 20717968 is about 274.6517597507.

The spelling of 20717968 in words is "twenty million, seven hundred seventeen thousand, nine hundred sixty-eight".