728121608 has 16 divisors (see below), whose sum is σ = 1366057980. Its totient is φ = 363839488.

The previous prime is 728121599. The next prime is 728121613. The reversal of 728121608 is 806121827.

It can be written as a sum of positive squares in 2 ways, for example, as 720492964 + 7628644 = 26842^2 + 2762^2 .

It is a super-2 number, since 2×728121608² = 1060322152073011328, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13241 + ... + 40392.

Almost surely, 2^728121608 is an apocalyptic number.

It is an amenable number.

728121608 is a deficient number, since it is larger than the sum of its proper divisors (637936372).

728121608 is a wasteful number, since it uses less digits than its factorization.

728121608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55336 (or 55332 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 728121608 is about 26983.7285785341. The cubic root of 728121608 is about 899.6383765285.

The spelling of 728121608 in words is "seven hundred twenty-eight million, one hundred twenty-one thousand, six hundred eight".