728409231 has 18 divisors (see below), whose sum is σ = 1156493520. Its totient is φ = 441459480.

The previous prime is 728409223. The next prime is 728409233. The reversal of 728409231 is 132904827.

It is not a de Polignac number, because 728409231 - 2³ = 728409223 is a prime.

It is a super-2 number, since 2×728409231² = 1061160015612022722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728409233) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 333351 + ... + 335528.

It is an arithmetic number, because the mean of its divisors is an integer number (64249640).

Almost surely, 2^728409231 is an apocalyptic number.

728409231 is a deficient number, since it is larger than the sum of its proper divisors (428084289).

728409231 is a wasteful number, since it uses less digits than its factorization.

728409231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668907 (or 668893 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 728409231 is about 26989.0576160043. The cubic root of 728409231 is about 899.7568194836.

The spelling of 728409231 in words is "seven hundred twenty-eight million, four hundred nine thousand, two hundred thirty-one".