20216420 has 60 divisors (see below), whose sum is σ = 49644924. Its totient is φ = 6914880.

The previous prime is 20216411. The next prime is 20216447. The reversal of 20216420 is 2461202.

It can be written as a sum of positive squares in 2 ways, for example, as 2458624 + 17757796 = 1568^2 + 4214^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 47810 + ... + 48230.

Almost surely, 2^20216420 is an apocalyptic number.

20216420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20216420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24822462).

20216420 is an abundant number, since it is smaller than the sum of its proper divisors (29428504).

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

20216420 is an equidigital number, since it uses as much as digits as its factorization.

20216420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 20216420 is about 4496.2673408061. The cubic root of 20216420 is about 272.4173415933.

Adding to 20216420 its reverse (2461202), we get a palindrome (22677622).

The spelling of 20216420 in words is "twenty million, two hundred sixteen thousand, four hundred twenty".