20017220 has 12 divisors (see below), whose sum is σ = 42036204. Its totient is φ = 8006880.

The previous prime is 20017189. The next prime is 20017223. The reversal of 20017220 is 2271002.

It can be written as a sum of positive squares in 2 ways, for example, as 4129024 + 15888196 = 2032^2 + 3986^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20017195 and 20017204.

It is not an unprimeable number, because it can be changed into a prime (20017223) 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, 500411 + ... + 500450.

It is an arithmetic number, because the mean of its divisors is an integer number (3503017).

Almost surely, 2^20017220 is an apocalyptic number.

20017220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20017220 is an abundant number, since it is smaller than the sum of its proper divisors (22018984).

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

20017220 is a wasteful number, since it uses less digits than its factorization.

20017220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000870 (or 1000868 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 14.

The square root of 20017220 is about 4474.0607952955. The cubic root of 20017220 is about 271.5196430974.

Adding to 20017220 its reverse (2271002), we get a palindrome (22288222).

It can be divided in two parts, 200 and 17220, that multiplied together give a triangular number (3444000 = T₂₆₂₄).

The spelling of 20017220 in words is "twenty million, seventeen thousand, two hundred twenty".