1720520 has 16 divisors (see below), whose sum is σ = 3871260. Its totient is φ = 688192.

The previous prime is 1720517. The next prime is 1720549. The reversal of 1720520 is 250271.

It can be written as a sum of positive squares in 2 ways, for example, as 1705636 + 14884 = 1306^2 + 122^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21467 + ... + 21546.

2^1720520 is an apocalyptic number.

1720520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1720520 is an abundant number, since it is smaller than the sum of its proper divisors (2150740).

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

1720520 is a wasteful number, since it uses less digits than its factorization.

1720520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43024 (or 43020 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 1720520 is about 1311.6859380202. The cubic root of 1720520 is about 119.8266014136.

Adding to 1720520 its reverse (250271), we get a palindrome (1970791).

The spelling of 1720520 in words is "one million, seven hundred twenty thousand, five hundred twenty".