728122001 has 4 divisors (see below), whose sum is σ = 747801012. Its totient is φ = 708442992.

The previous prime is 728121991. The next prime is 728122033. The reversal of 728122001 is 100221827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 100221827 = 19 ⋅5274833.

It can be written as a sum of positive squares in 2 ways, for example, as 643941376 + 84180625 = 25376^2 + 9175^2 .

It is a cyclic number.

It is not a de Polignac number, because 728122001 - 2¹⁰ = 728120977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (728122501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9839450 + ... + 9839523.

It is an arithmetic number, because the mean of its divisors is an integer number (186950253).

Almost surely, 2^728122001 is an apocalyptic number.

It is an amenable number.

728122001 is a deficient number, since it is larger than the sum of its proper divisors (19679011).

728122001 is a wasteful number, since it uses less digits than its factorization.

728122001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19679010.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 728122001 is about 26983.7358606995. The cubic root of 728122001 is about 899.6385383869.

Adding to 728122001 its reverse (100221827), we get a palindrome (828343828).

The spelling of 728122001 in words is "seven hundred twenty-eight million, one hundred twenty-two thousand, one".