28708308 has 72 divisors (see below), whose sum is σ = 78198120. Its totient is φ = 8847360.

The previous prime is 28708243. The next prime is 28708313. The reversal of 28708308 is 80380782.

It can be written as a sum of positive squares in 4 ways, for example, as 956484 + 27751824 = 978^2 + 5268^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 36948 + ... + 37716.

It is an arithmetic number, because the mean of its divisors is an integer number (1086085).

Almost surely, 2^28708308 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 28708308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39099060).

28708308 is an abundant number, since it is smaller than the sum of its proper divisors (49489812).

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

28708308 is a wasteful number, since it uses less digits than its factorization.

28708308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857 (or 852 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 28708308 is about 5358.0134378331. The cubic root of 28708308 is about 306.1981287686.

The spelling of 28708308 in words is "twenty-eight million, seven hundred eight thousand, three hundred eight".