28250000 has 70 divisors (see below), whose sum is σ = 69022554. Its totient is φ = 11200000.

The previous prime is 28249999. The next prime is 28250023. The reversal of 28250000 is 5282.

It is a happy number.

It can be written as a sum of positive squares in 7 ways, for example, as 24760576 + 3489424 = 4976^2 + 1868^2 .

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 13 ways as a sum of consecutive naturals, for example, 249944 + ... + 250056.

Almost surely, 2^28250000 is an apocalyptic number.

28250000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28250000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34511277).

28250000 is an abundant number, since it is smaller than the sum of its proper divisors (40772554).

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

28250000 is an frugal number, since it uses more digits than its factorization.

28250000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 28250000 is about 5315.0729063673. The cubic root of 28250000 is about 304.5599674460.

Adding to 28250000 its reverse (5282), we get a palindrome (28255282).

The spelling of 28250000 in words is "twenty-eight million, two hundred fifty thousand".