728181819 has 12 divisors (see below), whose sum is σ = 1090774776. Its totient is φ = 485454384.

The previous prime is 728181809. The next prime is 728181871. The reversal of 728181819 is 918181827.

It is a happy number.

It is not a de Polignac number, because 728181819 - 2⁷ = 728181691 is a prime.

It is a super-2 number, since 2×728181819² = 1060497523044297522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (728181809) 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 11 ways as a sum of consecutive naturals, for example, 1498074 + ... + 1498559.

It is an arithmetic number, because the mean of its divisors is an integer number (90897898).

Almost surely, 2^728181819 is an apocalyptic number.

728181819 is a deficient number, since it is larger than the sum of its proper divisors (362592957).

728181819 is an equidigital number, since it uses as much as digits as its factorization.

728181819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2996648 (or 2996636 counting only the distinct ones).

The product of its digits is 64512, while the sum is 45.

The square root of 728181819 is about 26984.8442463543. The cubic root of 728181819 is about 899.6631739582.

It can be divided in two parts, 728181 and 819, that added together give a cube (729000 = 90³).

The spelling of 728181819 in words is "seven hundred twenty-eight million, one hundred eighty-one thousand, eight hundred nineteen".