20684416 has 32 divisors (see below), whose sum is σ = 41998500. Its totient is φ = 10143744.

The previous prime is 20684413. The next prime is 20684423. The reversal of 20684416 is 61448602.

It can be written as a sum of positive squares in 2 ways, for example, as 20430400 + 254016 = 4520^2 + 504^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×20684416² = 855690130522112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20684413) 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, 5260 + ... + 8308.

Almost surely, 2^20684416 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 20684416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20999250).

20684416 is an abundant number, since it is smaller than the sum of its proper divisors (21314084).

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

20684416 is an equidigital number, since it uses as much as digits as its factorization.

20684416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3116 (or 3104 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 20684416 is about 4548.0123130880. The cubic root of 20684416 is about 274.5034167787.

The spelling of 20684416 in words is "twenty million, six hundred eighty-four thousand, four hundred sixteen".