1728869 has 4 divisors (see below), whose sum is σ = 1731660. Its totient is φ = 1726080.

The previous prime is 1728827. The next prime is 1728871. The reversal of 1728869 is 9688271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9688271 = 19 ⋅509909.

It can be written as a sum of positive squares in 2 ways, for example, as 12769 + 1716100 = 113^2 + 1310^2 .

It is a cyclic number.

It is not a de Polignac number, because 1728869 - 2²⁰ = 680293 is a prime.

It is a super-2 number, since 2×1728869² = 5977976038322, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1728809) 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, 2 + ... + 1859.

It is an arithmetic number, because the mean of its divisors is an integer number (432915).

2^1728869 is an apocalyptic number.

It is an amenable number.

1728869 is a deficient number, since it is larger than the sum of its proper divisors (2791).

1728869 is an equidigital number, since it uses as much as digits as its factorization.

1728869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2790.

The product of its digits is 48384, while the sum is 41.

The square root of 1728869 is about 1314.8646318158. The cubic root of 1728869 is about 120.0201123697.

The spelling of 1728869 in words is "one million, seven hundred twenty-eight thousand, eight hundred sixty-nine".