1720319 has 4 divisors (see below), whose sum is σ = 1762320. Its totient is φ = 1678320.

The previous prime is 1720307. The next prime is 1720321. The reversal of 1720319 is 9130271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9130271 = 2741 ⋅3331.

It is a cyclic number.

It is not a de Polignac number, because 1720319 - 2⁸ = 1720063 is a prime.

It is a super-2 number, since 2×1720319² = 5918994923522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1720294 and 1720303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20939 + ... + 21020.

It is an arithmetic number, because the mean of its divisors is an integer number (440580).

2^1720319 is an apocalyptic number.

1720319 is a deficient number, since it is larger than the sum of its proper divisors (42001).

1720319 is an equidigital number, since it uses as much as digits as its factorization.

1720319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42000.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 1720319 is about 1311.6093168318. The cubic root of 1720319 is about 119.8219349785.

The spelling of 1720319 in words is "one million, seven hundred twenty thousand, three hundred nineteen".