728889621 has 8 divisors (see below), whose sum is σ = 985541184. Its totient is φ = 479082240.

The previous prime is 728889617. The next prime is 728889691. The reversal of 728889621 is 126988827.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 728889621 - 2² = 728889617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728889691) 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 7 ways as a sum of consecutive naturals, for example, 1710796 + ... + 1711221.

It is an arithmetic number, because the mean of its divisors is an integer number (123192648).

Almost surely, 2^728889621 is an apocalyptic number.

728889621 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

728889621 is a deficient number, since it is larger than the sum of its proper divisors (256651563).

728889621 is a wasteful number, since it uses less digits than its factorization.

728889621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3422091.

The product of its digits is 774144, while the sum is 51.

The square root of 728889621 is about 26997.9558670652. The cubic root of 728889621 is about 899.9545742505.

The spelling of 728889621 in words is "seven hundred twenty-eight million, eight hundred eighty-nine thousand, six hundred twenty-one".