28728100 has 18 divisors (see below), whose sum is σ = 62340194. Its totient is φ = 11491200.

The previous prime is 28728097. The next prime is 28728121. The reversal of 28728100 is 182782.

It can be written as a sum of positive squares in 3 ways, for example, as 3748096 + 24980004 = 1936^2 + 4998^2 .

It is a super-2 number, since 2×28728100² = 1650607459220000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 143541 + ... + 143740.

Almost surely, 2^28728100 is an apocalyptic number.

28728100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28728100 is an abundant number, since it is smaller than the sum of its proper divisors (33612094).

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

28728100 is a wasteful number, since it uses less digits than its factorization.

28728100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287295 (or 287288 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 28728100 is about 5359.8600728004. The cubic root of 28728100 is about 306.2684786851.

The spelling of 28728100 in words is "twenty-eight million, seven hundred twenty-eight thousand, one hundred".