728213 has 4 divisors (see below), whose sum is σ = 766560. Its totient is φ = 689868.

The previous prime is 728209. The next prime is 728261. The reversal of 728213 is 312827.

728213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 312827 = 83 ⋅3769.

It is a cyclic number.

It is not a de Polignac number, because 728213 - 2² = 728209 is a prime.

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 (728293) 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, 19145 + ... + 19182.

It is an arithmetic number, because the mean of its divisors is an integer number (191640).

2⁷²⁸²¹³ is an apocalyptic number.

It is an amenable number.

728213 is a deficient number, since it is larger than the sum of its proper divisors (38347).

728213 is a wasteful number, since it uses less digits than its factorization.

728213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38346.

The product of its digits is 672, while the sum is 23.

The square root of 728213 is about 853.3539711046. The cubic root of 728213 is about 89.9676015072.

The spelling of 728213 in words is "seven hundred twenty-eight thousand, two hundred thirteen".