1720220220 has 96 divisors (see below), whose sum is σ = 5362909440. Its totient is φ = 457773120.

The previous prime is 1720220171. The next prime is 1720220221. The reversal of 1720220220 is 220220271.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1720220193 and 1720220202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720220221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 279375 + ... + 285465.

It is an arithmetic number, because the mean of its divisors is an integer number (55863640).

Almost surely, 2^1720220220 is an apocalyptic number.

1720220220 is a gapful number since it is divisible by the number (10) 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 1720220220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2681454720).

1720220220 is an abundant number, since it is smaller than the sum of its proper divisors (3642689220).

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

1720220220 is a wasteful number, since it uses less digits than its factorization.

1720220220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6632 (or 6624 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 1720220220 is about 41475.5376095356. The cubic root of 1720220220 is about 1198.1964155942.

Adding to 1720220220 its reverse (220220271), we get a palindrome (1940440491).

The spelling of 1720220220 in words is "one billion, seven hundred twenty million, two hundred twenty thousand, two hundred twenty".