728665400621 has 16 divisors (see below), whose sum is σ = 774865488000. Its totient is φ = 683286202368.

The previous prime is 728665400609. The next prime is 728665400623. The reversal of 728665400621 is 126004566827.

It is a cyclic number.

It is not a de Polignac number, because 728665400621 - 2¹⁰ = 728665399597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728665400623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 230465 + ... + 1229001.

It is an arithmetic number, because the mean of its divisors is an integer number (48429093000).

Almost surely, 2^728665400621 is an apocalyptic number.

It is an amenable number.

728665400621 is a deficient number, since it is larger than the sum of its proper divisors (46200087379).

728665400621 is a wasteful number, since it uses less digits than its factorization.

728665400621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998948.

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 728665400621 in words is "seven hundred twenty-eight billion, six hundred sixty-five million, four hundred thousand, six hundred twenty-one".