20209968 has 60 divisors (see below), whose sum is σ = 56871360. Its totient is φ = 6699648.

The previous prime is 20209967. The next prime is 20209993. The reversal of 20209968 is 86990202.

It is a super-2 number, since 2×20209968² = 816885613122048, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (20209961) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41953 + ... + 42431.

It is an arithmetic number, because the mean of its divisors is an integer number (947856).

Almost surely, 2^20209968 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 20209968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28435680).

20209968 is an abundant number, since it is smaller than the sum of its proper divisors (36661392).

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

20209968 is a wasteful number, since it uses less digits than its factorization.

20209968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786 (or 777 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 20209968 is about 4495.5497995240. The cubic root of 20209968 is about 272.3883581613.

The spelling of 20209968 in words is "twenty million, two hundred nine thousand, nine hundred sixty-eight".