20684288 has 40 divisors (see below), whose sum is σ = 41983920. Its totient is φ = 10178560.

The previous prime is 20684281. The next prime is 20684309. The reversal of 20684288 is 88248602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20684281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36068 + ... + 36636.

It is an arithmetic number, because the mean of its divisors is an integer number (1049598).

Almost surely, 2^20684288 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 20684288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20991960).

20684288 is an abundant number, since it is smaller than the sum of its proper divisors (21299632).

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

20684288 is an frugal number, since it uses more digits than its factorization.

20684288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 38.

The square root of 20684288 is about 4547.9982409847. The cubic root of 20684288 is about 274.5028505471.

The spelling of 20684288 in words is "twenty million, six hundred eighty-four thousand, two hundred eighty-eight".