728857321538 has 16 divisors (see below), whose sum is σ = 1110331898496. Its totient is φ = 358761943680.

The previous prime is 728857321537. The next prime is 728857321561. The reversal of 728857321538 is 835123758827.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (728857321537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3717806 + ... + 3908937.

It is an arithmetic number, because the mean of its divisors is an integer number (69395743656).

Almost surely, 2^728857321538 is an apocalyptic number.

728857321538 is a deficient number, since it is larger than the sum of its proper divisors (381474576958).

728857321538 is a wasteful number, since it uses less digits than its factorization.

728857321538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7627489.

The product of its digits is 22579200, while the sum is 59.

The spelling of 728857321538 in words is "seven hundred twenty-eight billion, eight hundred fifty-seven million, three hundred twenty-one thousand, five hundred thirty-eight".