728505231 has 4 divisors (see below), whose sum is σ = 971340312. Its totient is φ = 485670152.

The previous prime is 728505209. The next prime is 728505241. The reversal of 728505231 is 132505827.

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 728505231 - 2⁷ = 728505103 is a prime.

It is a super-2 number, since 2×728505231² = 1061439743188726722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 728505192 and 728505201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728505241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121417536 + ... + 121417541.

It is an arithmetic number, because the mean of its divisors is an integer number (242835078).

Almost surely, 2^728505231 is an apocalyptic number.

728505231 is a deficient number, since it is larger than the sum of its proper divisors (242835081).

728505231 is a wasteful number, since it uses less digits than its factorization.

728505231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242835080.

The product of its (nonzero) digits is 16800, while the sum is 33.

The square root of 728505231 is about 26990.8360559654. The cubic root of 728505231 is about 899.7963452779.

The spelling of 728505231 in words is "seven hundred twenty-eight million, five hundred five thousand, two hundred thirty-one".