1720531 has 4 divisors (see below), whose sum is σ = 1776064. Its totient is φ = 1665000.

The previous prime is 1720517. The next prime is 1720549. The reversal of 1720531 is 1350271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1350271 = 13 ⋅103867.

It is a cyclic number.

It is not a de Polignac number, because 1720531 - 2¹³ = 1712339 is a prime.

It is a super-2 number, since 2×1720531² = 5920453843922, 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 = 1720499 and 1720508.

It is not an unprimeable number, because it can be changed into a prime (1720591) 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, 27720 + ... + 27781.

It is an arithmetic number, because the mean of its divisors is an integer number (444016).

2^1720531 is an apocalyptic number.

1720531 is a deficient number, since it is larger than the sum of its proper divisors (55533).

1720531 is an equidigital number, since it uses as much as digits as its factorization.

1720531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55532.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 1720531 is about 1311.6901310904. The cubic root of 1720531 is about 119.8268567802.

The spelling of 1720531 in words is "one million, seven hundred twenty thousand, five hundred thirty-one".