728215 has 4 divisors (see below), whose sum is σ = 873864. Its totient is φ = 582568.

The previous prime is 728209. The next prime is 728261. The reversal of 728215 is 512827.

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 728215 - 2³ = 728207 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 728215.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72817 + ... + 72826.

It is an arithmetic number, because the mean of its divisors is an integer number (218466).

2⁷²⁸²¹⁵ is an apocalyptic number.

728215 is a deficient number, since it is larger than the sum of its proper divisors (145649).

728215 is a wasteful number, since it uses less digits than its factorization.

728215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145648.

The product of its digits is 1120, while the sum is 25.

The square root of 728215 is about 853.3551429505. The cubic root of 728215 is about 89.9676838709.

It can be divided in two parts, 728 and 215, that multiplied together give a triangular number (156520 = T₅₅₉).

The spelling of 728215 in words is "seven hundred twenty-eight thousand, two hundred fifteen".