728508638 has 48 divisors (see below), whose sum is σ = 1315570896. Its totient is φ = 299819520.

The previous prime is 728508617. The next prime is 728508643. The reversal of 728508638 is 836805827.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 728508592 and 728508601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 195206 + ... + 198902.

It is an arithmetic number, because the mean of its divisors is an integer number (27407727).

Almost surely, 2^728508638 is an apocalyptic number.

728508638 is a deficient number, since it is larger than the sum of its proper divisors (587062258).

728508638 is a wasteful number, since it uses less digits than its factorization.

728508638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3789 (or 3776 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 47.

The square root of 728508638 is about 26990.8991699054. The cubic root of 728508638 is about 899.7977479681.

The spelling of 728508638 in words is "seven hundred twenty-eight million, five hundred eight thousand, six hundred thirty-eight".