28000008 has 48 divisors (see below), whose sum is σ = 76347180. Its totient is φ = 9270144.

The previous prime is 27999943. The next prime is 28000019. The reversal of 28000008 is 80000082.

It can be written as a sum of positive squares in 2 ways, for example, as 27688644 + 311364 = 5262^2 + 558^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

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 11 ways as a sum of consecutive naturals, for example, 10066 + ... + 12542.

Almost surely, 2^28000008 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28000008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38173590).

28000008 is an abundant number, since it is smaller than the sum of its proper divisors (48347172).

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

28000008 is a wasteful number, since it uses less digits than its factorization.

28000008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646 (or 2639 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 28000008 is about 5291.5033780581. The cubic root of 28000008 is about 303.6589261075.

The spelling of 28000008 in words is "twenty-eight million, eight", and thus it is an aban number and an uban number.