728457 has 4 divisors (see below), whose sum is σ = 971280. Its totient is φ = 485636.

The previous prime is 728437. The next prime is 728471. The reversal of 728457 is 754827.

728457 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: 754827 = 3 ⋅251609.

It is a cyclic number.

It is not a de Polignac number, because 728457 - 2¹⁵ = 695689 is a prime.

It is a D-number.

728457 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (728417) 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, 121407 + ... + 121412.

It is an arithmetic number, because the mean of its divisors is an integer number (242820).

2⁷²⁸⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

728457 is a deficient number, since it is larger than the sum of its proper divisors (242823).

728457 is a wasteful number, since it uses less digits than its factorization.

728457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242822.

The product of its digits is 15680, while the sum is 33.

The square root of 728457 is about 853.4969244233. The cubic root of 728457 is about 89.9776487706.

The spelling of 728457 in words is "seven hundred twenty-eight thousand, four hundred fifty-seven".