1728215 has 4 divisors (see below), whose sum is σ = 2073864. Its totient is φ = 1382568.

The previous prime is 1728193. The next prime is 1728229. The reversal of 1728215 is 5128271.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1728215 - 2¹⁰ = 1727191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172817 + ... + 172826.

It is an arithmetic number, because the mean of its divisors is an integer number (518466).

2^1728215 is an apocalyptic number.

1728215 is a deficient number, since it is larger than the sum of its proper divisors (345649).

1728215 is an equidigital number, since it uses as much as digits as its factorization.

1728215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345648.

The product of its digits is 1120, while the sum is 26.

The square root of 1728215 is about 1314.6159134896. The cubic root of 1728215 is about 120.0049766455.

The spelling of 1728215 in words is "one million, seven hundred twenty-eight thousand, two hundred fifteen".