728431 has 4 divisors (see below), whose sum is σ = 794664. Its totient is φ = 662200.

The previous prime is 728423. The next prime is 728437. The reversal of 728431 is 134827.

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

It is not a de Polignac number, because 728431 - 2³ = 728423 is a prime.

It is a super-2 number, since 2×728431² = 1061223443522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 728396 and 728405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33100 + ... + 33121.

It is an arithmetic number, because the mean of its divisors is an integer number (198666).

2⁷²⁸⁴³¹ is an apocalyptic number.

728431 is a deficient number, since it is larger than the sum of its proper divisors (66233).

728431 is a wasteful number, since it uses less digits than its factorization.

728431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66232.

The product of its digits is 1344, while the sum is 25.

The square root of 728431 is about 853.4816928324. The cubic root of 728431 is about 89.9765782674.

The spelling of 728431 in words is "seven hundred twenty-eight thousand, four hundred thirty-one".