728621805 has 32 divisors (see below), whose sum is σ = 1181174400. Its totient is φ = 383496192.

The previous prime is 728621801. The next prime is 728621813. The reversal of 728621805 is 508126827.

It is not a de Polignac number, because 728621805 - 2² = 728621801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728621801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900241 + ... + 901049.

It is an arithmetic number, because the mean of its divisors is an integer number (36911700).

Almost surely, 2^728621805 is an apocalyptic number.

It is an amenable number.

728621805 is a deficient number, since it is larger than the sum of its proper divisors (452552595).

728621805 is a wasteful number, since it uses less digits than its factorization.

728621805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1533.

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 728621805 is about 26992.9954803093. The cubic root of 728621805 is about 899.8443372759.

The spelling of 728621805 in words is "seven hundred twenty-eight million, six hundred twenty-one thousand, eight hundred five".