728421188891 has 16 divisors (see below), whose sum is σ = 795770459136. Its totient is φ = 661260600000.

The previous prime is 728421188867. The next prime is 728421188897. The reversal of 728421188891 is 198881124827.

It is not a de Polignac number, because 728421188891 - 2³⁴ = 711241319707 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 728421188891.

It is not an unprimeable number, because it can be changed into a prime (728421188897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36777191 + ... + 36796991.

It is an arithmetic number, because the mean of its divisors is an integer number (49735653696).

Almost surely, 2^728421188891 is an apocalyptic number.

728421188891 is a deficient number, since it is larger than the sum of its proper divisors (67349270245).

728421188891 is a wasteful number, since it uses less digits than its factorization.

728421188891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24394.

The product of its digits is 4128768, while the sum is 59.

The spelling of 728421188891 in words is "seven hundred twenty-eight billion, four hundred twenty-one million, one hundred eighty-eight thousand, eight hundred ninety-one".