20216220 has 48 divisors (see below), whose sum is σ = 56827008. Its totient is φ = 5369920.

The previous prime is 20216201. The next prime is 20216221. The reversal of 20216220 is 2261202.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 20216220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20216221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20335 + ... + 21305.

It is an arithmetic number, because the mean of its divisors is an integer number (1183896).

Almost surely, 2^20216220 is an apocalyptic number.

20216220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20216220 is an abundant number, since it is smaller than the sum of its proper divisors (36610788).

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

20216220 is a wasteful number, since it uses less digits than its factorization.

20216220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330 (or 1328 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 20216220 is about 4496.2451000807. The cubic root of 20216220 is about 272.4164432535.

Adding to 20216220 its reverse (2261202), we get a palindrome (22477422).

The spelling of 20216220 in words is "twenty million, two hundred sixteen thousand, two hundred twenty".