28728198 has 48 divisors (see below), whose sum is σ = 66358656. Its totient is φ = 8951040.

The previous prime is 28728197. The next prime is 28728211. The reversal of 28728198 is 89182782.

It is a happy number.

28728198 is a `hidden beast` number, since 287 + 281 + 98 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728191) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68028 + ... + 68448.

It is an arithmetic number, because the mean of its divisors is an integer number (1382472).

Almost surely, 2^28728198 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28728198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33179328).

28728198 is an abundant number, since it is smaller than the sum of its proper divisors (37630458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28728198 is a wasteful number, since it uses less digits than its factorization.

28728198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669 (or 666 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 28728198 is about 5359.8692148223. The cubic root of 28728198 is about 306.2688269420.

The spelling of 28728198 in words is "twenty-eight million, seven hundred twenty-eight thousand, one hundred ninety-eight".