728533381 has 4 divisors (see below), whose sum is σ = 729378432. Its totient is φ = 727688332.

The previous prime is 728533373. The next prime is 728533433. The reversal of 728533381 is 183335827.

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: 183335827 = 3253 ⋅56359.

It is a cyclic number.

It is not a de Polignac number, because 728533381 - 2³ = 728533373 is a prime.

It is a super-2 number, since 2×728533381² = 1061521774462582322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728533781) 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, 421231 + ... + 422956.

It is an arithmetic number, because the mean of its divisors is an integer number (182344608).

Almost surely, 2^728533381 is an apocalyptic number.

It is an amenable number.

728533381 is a deficient number, since it is larger than the sum of its proper divisors (845051).

728533381 is an equidigital number, since it uses as much as digits as its factorization.

728533381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845050.

The product of its digits is 120960, while the sum is 40.

The square root of 728533381 is about 26991.3575242150. The cubic root of 728533381 is about 899.8079347352.

The spelling of 728533381 in words is "seven hundred twenty-eight million, five hundred thirty-three thousand, three hundred eighty-one".