1720172020 has 48 divisors (see below), whose sum is σ = 4261598208. Its totient is φ = 570746880.

The previous prime is 1720172017. The next prime is 1720172021. The reversal of 1720172020 is 202710271.

It is a junction number, because it is equal to n+sod(n) for n = 1720171982 and 1720172000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720172021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193837 + ... + 202516.

It is an arithmetic number, because the mean of its divisors is an integer number (88783296).

Almost surely, 2^1720172020 is an apocalyptic number.

1720172020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1720172020 is an abundant number, since it is smaller than the sum of its proper divisors (2541426188).

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

1720172020 is a wasteful number, since it uses less digits than its factorization.

1720172020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396400 (or 396398 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 1720172020 is about 41474.9565400616. The cubic root of 1720172020 is about 1198.1852244676.

Adding to 1720172020 its reverse (202710271), we get a palindrome (1922882291).

The spelling of 1720172020 in words is "one billion, seven hundred twenty million, one hundred seventy-two thousand, twenty".