728851681 has 4 divisors (see below), whose sum is σ = 730755072. Its totient is φ = 726948292.

The previous prime is 728851679. The next prime is 728851687. The reversal of 728851681 is 186158827.

728851681 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: 186158827 = 19 ⋅9797833.

It is a cyclic number.

It is not a de Polignac number, because 728851681 - 2¹ = 728851679 is a prime.

It is a super-2 number, since 2×728851681² = 1062449545793051522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728851687) 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, 951121 + ... + 951886.

It is an arithmetic number, because the mean of its divisors is an integer number (182688768).

Almost surely, 2^728851681 is an apocalyptic number.

It is an amenable number.

728851681 is a deficient number, since it is larger than the sum of its proper divisors (1903391).

728851681 is a wasteful number, since it uses less digits than its factorization.

728851681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903390.

The product of its digits is 215040, while the sum is 46.

The square root of 728851681 is about 26997.2532121325. The cubic root of 728851681 is about 899.9389592346.

The spelling of 728851681 in words is "seven hundred twenty-eight million, eight hundred fifty-one thousand, six hundred eighty-one".